2point4 Children: In an early episode, Rona's Aunt Pearl claims to have got married during World War II. A later episode reveals that she is Rona's real mother and gave her up for adoption in 1957, because Pearl wasn't married "yet" and unwed motherhood was considered a disgrace at the time.
In one episode of The Addams Family, Gomez and Morticia are looking through their belongings and find Morticia's wedding dress. Yet in the flashback episode that tells the story of how they fell in love and got married, Morticia is shown wearing the dress she always wears during the wedding, declaring "I'll never wear another!" when Gomez compliments it.
The Adventures of Superman has one episode in which Jimmy gives his middle name as Bartholomew, and another where a nameplate says "James J. Olsen".
Agents of S.H.I.E.L.D.: "Paradise Lost" has a flashback in which a young Gideon Malick and his brother Nathaniel visit Werner Reinhardt in prison. They refer to Reinhardt as Daniel Whitehall, his present-day alias, which he did not begin to use until after he was freed.
Aliens in America has an episode about Justin's fear of performing in public — it's a plot point that he's a weak singer who freezes up so badly on stage that he wasn't allowed to sing in a school pageant that offered a role to anyone who showed up. A few episodes later, Justin's been a soloist in the school choir for years.
Angel has a big Season Two plot point of Angel offering to turn the terminally ill Darla back into a vampire because "he's never tried turning someone into a vampire after he got a soul" in the hopes that he might make her a good vampire. Apparently, the writers forgot this major plot point when they created an episode in Season Five where Angel has a flashback to doing just that during World War II, and it didn't turn out well.
While Bates Motel (1987) presumably tried to avoid this trope by treating Psycho II and Psycho III as being in Canon Discontinuity, it still manages to significantly screw up continuity with the original Psycho, changing the name of Norman Bates's mother from Norma to Gloria, and showing that Norman buried her corpse on the hotel grounds, even though there was no possible way he could have done that after being caught in the film's climax.
Dylan McKay is an alcoholic during his first run on Beverly Hills, 90210. When he returned after a few seasons' absence he drank socially and no one commented on his previous alcoholism (but he became a drug addict).
In one episode, Sheldon admonishes Leonard for ending a sentence with a preposition. Anyone with even a cursory ability to recognise grammatical structures would remember that Sheldon has never been averse to this. This may be because the writers didn't think anyone would notice when they came up with the gag, or because the writers didn't know anything about the "taboo" of ending sentences with prepositions until they wrote that gag and then promptly forgot about it afterwards. On the other hand, Sheldon has often been proven to be a hypocrite, so the error is completely in line with his character.
In another episode, Sheldon asserts that he never forgets anything. Later in the same episode, when he is listing all of the actresses who have played Catwoman, Howard points out that he left out Lee Meriwether. "Oh. I forgot about Lee Meriwether". Unfortunately, it doesn't appear that the writers caught the joke. Justified as Sheldon is known for massively overestimating his own intelligence. note He also forgot Maggie Baird, who played the role in Birds of Prey (2002) for all of one scene, but that one's presumably on the writers.
Another odd one: In an early episode when Sheldon is gone, Penny suggests that Leonard and she sit in his spot and make out, to which he approvingly says "You're a dirty girl!", unfortunately for them (and the audience) they are interrupted before they can start. In a much later episode, Leonard says they should have sex in Sheldon's spot, to which Penny inexplicably says that's the least sexy thing you've ever said.
Many details about Sheldon's childhood contradict each other, especially when the Spin-OffYoung Sheldon started airing.
Within Big Bang, season one suggested that George Cooper had only recently passed away (Missy brings documents from George's estate for Sheldon to sign and when Mary seduces Dr. Gablehauser to get Sheldon his job back, Mary says George has been dead "long enough" in a tone suggesting it wasn't really that long ago. Also, in "The Pancake Batter Anomaly", Sheldon said at the age of 15, he got sick in Germany, and his mother had to fly back to Texas to help his dad at that time.) but later episodes established that Sheldon was 14 when his father died, over a decade before the first season. George is also described posthumously as being an abusive, idiotic, misogynistic, drunken redneck whose constant fighting with Mary traumatized Sheldon to the point where he cannot stand to hear arguing of any kind. Young Sheldon portrays George as your average Bumbling Dad who treats his family well despite the occasional petty squabble.
Exactly when Sheldon went to college and how many grades he had skipped beforehand is also inconsistent. The pilot suggests he had at least a couple years of high school (as he mocks Penny for taking four years to graduate high school). A later season one episode states that Sheldon went to college after fifth grade at age 11. Then George Jr. says that Sheldon started college after their father's passing. Young Sheldon has Sheldon starting high school at age nine and auditing a physics course at a nearby college, with him not attending full-time until 11.
Brennan tells Booth in an early episode that her grandfather got her out of foster care, but this is later contradicted and she basically aged out.
There are inconsistencies on when Brennan's parents disappeared, with her indicating she was young at one point and saying she didn't have very many memories of them, and later being said to be 15. The time of year they left changed too. Fans theorize maybe she wasn't comfortable telling Booth the truth yet, but can't prove it.
Booth told Brennan he loved his dad, even though his dad was actually an abusive jerk and Booth hated him. He did say his grandfather was his real dad, so he may have been referring to that or just not wanting to tell Brennan the truth yet, as he's notoriously unwilling to talk about that part of his life.
Brennan doesn't seem to have met Cam in the season 2 opener, yet the 100th episode reveals they worked together on a case before the pilot, meaning they had at least met before.
Brennan says she worked identifying bodies from the Waco incident, but she would have still been a teenager at the time given what we know about her age.
In season one of Boy Meets World, Mr. Feeny informs his students that they will be the high school class of 2000. The characters actually graduate five seasons later, in 1998.
both Shawn and Topanga used to have a sister in earlier seasons that mysteriously disappeared.
In one episode of Brooklyn Nine-Nine, Holt says that he only uses contractions (ie. can’t, won’t…) when he’s lying. However, in pretty much every episode before and after this, he uses contractions in his speech at a more or less normal rate, including at times when he’s definitely not lying.
In Season 6, Buffy recounts the time when she first got her powers and her parents had her committed into a mental institution when she started talking about slaying vampires. Except, the Season 2 Finale has Buffy finally "coming out of the closet" as a Slayer to her mother who reacts like this is the first time she's ever heard of this fact. The Series Pilot episode even has Joyce dropping Buffy off at the new school and telling her that she doesn't want to be disappointed in her again, which would be an awful callous thing to say who was just released from psychiatric care after a month or so.
In Season 7, Spike is "tortured" by the Turok-Han by being drowned, despite the show and its spin-off, Angel, explicitly and repeatedly stating that vampires don't breathe. Apparently the First, the Turok-Han and Spike himself all forgot that little detail. The apparent Word of God is that it was supposed to be holy water; they simply forgot to add smoke and sizzling noises.
Whether or not vampires breathe is handled very inconsistently. Angel couldn't do CPR and survived three months underwater, but he could speak and Spike smoked. Maybe vampires can breathe but don't need to, though that wouldn't explain inability to do CPR. Except, of course, the potential ramifications of breathing air from inside a dead body directly into the lungs... even assuming no vampiric infection can occur, one would think the inside of an undead creature's throat would be a breeding ground of various bacteria, mold, and such.
Buffy's birthday changed a lot. Hell, it even changed once during the same episode — the camera cut away from a computer screen displaying her date of birth, and then cut right back to it displaying another one. The discrepancy in one episode could be explained as being All Just a Dream, and not Buffy's at that.
Warren's presence in the season eight comics caused a continuity error: The First had impersonated him many times in season seven, but it can only take on the appearance of people who have died. Joss Whedon said that he died briefly but was revived by Amy, but she lied and said he never died, which really just means that the writers all forgot.
The First depicted Warren with skin, while everyone else who has been magically reanimated have their depictions remain "up to date". This is most obvious with Adam, but that's clearly vampire Drusilla and the Master also, and the First explicitly has the same injury as Buffy at the end. (Glory and the Mayor both looked different than when they died, but they both were humans and demons body-swapping, so that can be handwaved... that's what Glory and the mayor looked like, not what Ben or Mayor-demon looked like. Or maybe this is just 'ghost logic' where dead people looked like they looked 'when alive' and yet despite having a gunshot hole through their torso for the last four seconds of their life, somehow don't walk around with it for eternity.) But the rule if a once-dead person is currently walking around (alive or not) the First is current on how they look. Warren being retconned to alive breaks the pattern. This is, of course, assuming there were any rules and that the First wasn't just picking a random appearance.
Whether or not stakes disappear with a vampire was terribly inconsistent. There were some instances when the stake would turn to dust, but other times it wouldn't and would fall to the floor. There doesn't seem to be any apparent pattern, either.
Buffy's powers are treated very inconsistently, particularly her level of strength. One episode she can demolish a house, in another she can't bust open a door. The second episode "The Harvest" shows her jumping over a 20 ft fence with ease, but she spends the majority of the season six finale unable to escape out of a small crater. She can tank incapacitating taser blasts fine and survive a lethal jolt of electricity, yet is rendered unconscious with a cattle prod.
In the hundredth episode, Paige sees her own grave in an alternate universe, which states her birth as being in 1975. However, in the episode after she was introduced, she states that she last saw the nun she was taken to as a baby on August 2nd, 1977, and it's heavily implied that this was the same night her parents took her to the church to be adopted, the night she was born. Even if this implication were to be discarded, Paige's older sister Phoebe is established to have been born in very late 1975, and it's also established that Phoebe was a toddler when Paige was conceived, so they weren't twins. As such, the only explanation which makes sense is that the writers forgot the year Paige was supposed to be born in (or, of course, that in an alternate universe Paige was born nearly two years earlier and no-one mentioned it).
In a season 1 episode, we learn that the girls' mother died shortly after Phoebe was born, MUCH too shortly after to have conceived and borne another child post-Phoebe. And yet, in a Season 2 episode, much earlier than when Paige became necessary as a character to replace Prue, their mother's date of death is established as February 28, 1978.
The girls' father was named Victor Halliwell in season 1, but later his name was Bennet and Halliwell was a name that had been passed from mother to daughter in defiance of social convention for an unspecified period of time.
Paige was there when the sisters first vanquished the Source, and still there when they did it a few more times. But in the final season, when the Source is temporarily resurrected, she asks "how did you do it?", which is very odd. The same episode implies that they vanquished him with a potion, when they actually used a spell.
Penny, the sisters' grandmother, was first mentioned to have married six times. This was later changed to that she had only been married four times but engaged six times.
In Chris's introduction episode - where he travels from the future - he orbs into the attic. In "Chris Crossed", showing the flashbacks to this, he travels by drawing a portal in the attic wall instead. Also he had short hair when he first appeared, which had grown out in Season 6, yet the flashbacks show the hair at its present length. Which suggests for some reason he got a haircut before saving the sisters' lives.
Chris arrives saving Paige from a Titan, and claims that she died on this day in his original timeline. Several episodes later he makes a throwaway comment about borrowing money from Paige in the future. Fans have tried to Hand Wave this by saying that his memories of the future change with each difference he makes in the past.
The series has a general problem remembering the details of how things were introduced.
The first time a character "blinks" (one specific form of teleportation), it's a warlock, but it's outright stated that the power must have been stolen from a witch. Killing witches to steal their powers remains a warlock's schtick, but blinking becomes an inherent warlock power, to the point that the sisters blinking is proof that they've been turned evil.
Leo first appears as a handyman with a supernatural secret, and when Phoebe catches him levitating, he explains that he's a whitelighter, a "guardian angel" type who's there to provide guidance for witches without getting directly involved in their lives. Shortly after, it's established that witches are supposed to know and bond with their whitelighters (though romance is still forbidden), to the point that Leo's replacement is a Drill Sergeant Nasty, so the whole "just passing through" thing doesn't make any sense. Whitelighters do have charges they're supposed to help and move on from, but those are explicitly mortal future-whitelighters who aren't ready to know about The Masquerade.
When Leo first mentions his superiors, he says they're "A group of elder whitelighters, called the Founders." Thereafter, they're called the Elders (and both names would be nonindicative, since we see them induct a novice teenager, so "Elder" status doesn't refer to age or prestige).
Memory dust is introduced via Sam, a former whitelighter, and Leo mentions that he must have stashed some away from a former witch charge. Later, memory dust is a whitelighter tool doled out directly from the Elders (Sam still would have had to stash some, considering he was no longer in contact with the Elders, but Leo did specify it would have come from a witch), and while Leo's hesitance at using memory dust could mean he'd lied so that the sisters wouldn't start asking for it, that doesn't cover the fact that they later know exactly where it comes from without someone revealing it to them.
The sisters themselves didn't know anything about being witches until the start of the series (thanks to their Grams wiping their memories- Prue and Piper were fully aware of being witches as young children). Later seasons start acting like they'd been raised as witches, with Paige sometimes being the one out of the loop, sometimes also being in the know. There's even a flashback to Piper being attacked by a demon in her father's presence after her mother's death (at the very least, she shouldn't have remembered the incident).
In "Cooperative Calligraphy", the Dean continually makes announcements about a puppy parade taking place in the quad, and it's heavily implied that the study group are the only seven students too involved in their own Serious Business to attend. In "Alternative History of the German Invasion", the incident is mentioned as one where other students also needed the room and in the flashbacks there are several students around the library very much unconcerned with the parade.
In "Alternative History of the German Invasion", the group's Dungeons and Dragons game took place at night (when no other students would care about the room), but is here shown taking place during the day, with plenty of other students mad that the room is occupied.
In "GI Jeff", Jeff states he turned 40. However, in "Intro to Political Science" Jeff claims he was 19 when he auditioned for The Real World Seattle, which would have been sometime in 1997, meaning Jeff would've been born in 1978, making him 36 at the time of the season. This is further contradicted by "Cooperative Escapism In Familial Relations" in which Jeff mentions having been in 7th grade "22 years ago". Assuming Jeff was 13 in 7th grade, this would make him 35 at the time of the episode, and again give a birth year of 1978.
In the first episode, Claire asks Cliff "Why do we have four children?" and he answers "Because we didn't want five." Only a few episodes later, viewers are introduced to college student Sondra, the oldest of their five children. According to Word of God, it was felt to be appropriate that the couple be shown with a college-age child and demonstrate to viewers what was expected of the other children.
In an early episode Cliff's office door shows his name as Clifford. Subsequent episodes established his name as Heathcliff.
At the end of a third-season episode, Prentiss is disturbed by the case the team just solved, saying that the killer was the first unsub she worked on who wasn't a bad guy. This means that Prentiss somehow thought that the unsub from the earlier episode "Distress" was a bad guy, she forgot about him, or the writers forgot about him.
In one episode it is an actual plot point that Garcia has four brothers. In another, she needs an explanation of normal sibling behavior, since she's an only child. Fans Handwave this by pointing out she has a stepfather, so it's possible they're stepbrothers or much younger half-brothers that she didn't grow up with.
Hotch either married Haley directly out of high school or five years before the series starts, depending on which episode you watch.
The case that haunted Rossi enough to bring him back to the BAU: originally he tells it that four children watched their parents be beaten to death on Christmas Eve. When the case is actually solved, it was only three children, who found their parents' bodies, after they were killed with an ax in March.
In the pilot episode Gideon makes it quite clear there is no such thing as a serial killer with multiple personalities, referencing a paper he's written. Well, there weren't until they actually encounter one, and Gideon makes no objection when the possibility is brought up.
Sara mentions a brother, then later says she was an only child.
Several items that were on the official CSI website character bios were changed in onscreen canon, like Catherine being from Bozeman, MT (later given to CSI:NY's Lindsay instead) and Grissom's father being involved in smuggling.
When Hodges breaks up with Elizabetta, the Italian woman he nearly married in a later season of the original series, part of the reason he panics is she wants to move back to Italy and have kids. But in the 2021 revival, Hodges has a wife who’s pregnant with their kid and the season ends with the baby’s birth. People do change their minds about kids, and unplanned kids do happen, but it still feels like an error to some fans.
Mac tells the victim in the series pilot that he used to sit with his wife in the hospital, the indication being that she was found after 9/11 and died of her injuries. But later, the story was changed to no body ever being found. Some have fanwanked that perhaps she was ill before.
Stella.
She tells a character in Season 1 that she lived at St. Basil's orphanage until age 18, but Season 3 has an ep with a big plot point being that Stella lived with a foster sister who was molested and eventually killed her attacker, and that the two of them were so close they became blood sisters. Late in Season 5, this is retconned that her mentor had "rescued" her from foster care and took her to live in the orphanage where he taught school.
Other problems with her timeline revolve around her age, including (but not limited to) her saying late in S5 that she was born in 1975, making her 34 at that point... when Mac says in the same ep that they'd been working together more than 10 years... but earlier on she said she'd worked for a number of years in Narcotics before moving to the Lab, and he never worked with that unit. It gave some fans quite a headache trying to figure it all out, others gave up completely.
Danny's original background never mentions law enforcement, only his brother being in a gang and them trying to recruit him. Then in season 6, he says he's from "a family of cops," making fans wonder where that came from. Some speculated that it was extended family, others didn't buy it.
Flack only mentions his mother and a brother once early in Season 4. His *sister* shows up in the Season 5 finale and pops in and out for around three years. Their conversations about their father and a few flashbacks to their childhood imply that the man had raised only the two of them after their mother's death.
Christine's late brother, who was Mac's friend/partner, was "Stan Whitney" officially, but she addresses him as "Stephen" during a flashback in her first episode in Season 8. She refers to him as "Stan" in every present-day scene thereafter, tho.
The Dick Van Dyke Show: Mel is consistently described as Alan Brady's brother-in-law; however, sometimes he's said to be married to Alan's sister, and other times Alan is said to be married to Mel's sister. (Of course, both could be true, though that strange scenario wouldn't be our first assumption, and the question would become why it's never brought up.)
In general, the show has even come up with an in-universe explanation which can act as a general retcon whenever needed; the Time War has just gone around screwing with the timeline! Whole events have literally been wiped out of existence (unless you're a time traveler, because then you can remember them).
In the earliest episodes, they talked about the ship. TARDIS was only Susan's nickname for it. However, since other Time Lords and the TARDIS herself, in "The Doctor's Wife", refer to the machine in question as such, this more likely either a very early Retcon or Early-Installment Weirdness. Although, confusingly, it is also referred to as a "TT Capsule" (presumable Time Travel) by a great many Time Lords as well, in the stories that take place on Gallifrey during the Fourth Doctor's time. This is given a fix by Big Finish Doctor Who in the audio drama The Beginning; the First Doctor calls it "the Ship", as he does in the series, but when Susan first mentions "TARDIS" he replies "Oh, you've heard that name". She thinks he's being silly and continues to think of it as her own name for the Ship, but the implication is that she wasn't the first to coin the acronym.* In the televised series, Susan herself seemed to think the name is extremely obvious. When she first mentioned it to Ian and Barbara — at that point two schoolteachers from the 1960s with no experience of time travel who'd just blundered their way into the TARDIS — she was quite surprised that they weren't able to decode its meaning. This may support the idea that other Time Lords would also come up with the same acronym. Another explanation comes from the BBC-produced "TARDIS Type 40 Instruction Manual". Yes, Susan did coin the name, and the Doctor started using it. Time Lords travelling around in their TT Capsules would visit a planet and find that (a) the Doctor had been there already and, as a result, (b) the inhabitants recognised "a TARDIS" when they saw one. Eventually the Time Lords ended up adopting the name as well.
The original series had been on for over a decade before they ever addressed the issue of the Doctor and his companions being able to understand the natives no matter what era they were in or planet they were on. When a companion actually made mention of it after having been travelling with him for several years, it was a big deal and a clue that someone was controlling her mind. In the new series, it's been brought up several times with the Doctor being unconcerned that they've noticed. The methodology, however, has changed; in the original series it is described as a "Time Lord gift" (suggesting the Doctor gave his companions the ability); in the revival, it's explicitly the TARDIS doing it via Psychic Link with the Doctor, and it doesn't work if she's too far away or he's unconscious.
There are many, many examples of characters getting obvious (although not drastic) haircuts and similar appearance alterations between supposedly consecutive episodes. The Chief Scientist in "The War Games" suddenly grows a beard over a few hours plot time; the Doctor in "The Ark in Space" gets his long hair layered while brooding in a cryogenic chamber anticipating an attack from the Wirrn; Barbara in one story gets captured, spends an episode imprisoned, and escapes with a new tan; Harry's sideburns get noticeably trimmed while in mid-teleport...
The modern-day series isn't immune to this. The 2014 episode "Flatline" has a rather notorious example where the Doctor's hairstyle completely changes between shots due to the actor having gotten a haircut at some point. Clara Oswald's hairstyle also changes between camera shots in the 2015 episodes "Face the Raven" and "Hell Bent".
In "The War Machines", the computer WOTAN actually says "Doctor Who is required". Even the most casual fans know that he isn't called that. The name is only ever used as a joke, e.g. "Doctor? Doctor who?" Except when it isn't, such as the Second Doctor signing his name "Dr. W" in one episode and using a non-English version of "Doctor Who" as an alias once. And there's the fact he uses the name "WHO" on the licence plate for Bessie...
The show has two different origins for the Loch Ness monster: an alien cyborg ("Terror of the Zygons") and a mutated overlord thrown back in time ("Timelash"). Similarly, there has been at least three and up to five monsters who are Satan — Azal ("The Dæmons"), Sutekh ("Pyramids of Mars"), the Beast ("The Satan Pit"), arguably the Black Guardian (the Key to Time Arc) and Scratchman, depending on whether you want to consider an unmade film part of the Whoniverse or not.
The notorious UNIT dating problem: In "Pyramids of Mars", Sarah Jane Smith is from 1980, and the last time she was there, the Brigadier was still heading UNIT ("Terror of the Zygons"). In "Mawdryn Undead", the Brigadier retired in 1976, taking up a position as mathematics teacher through 1983. Lampshaded in the series 4 episode "The Sontaran Stratagem", when the Doctor tells Donna he used to work for UNIT in the '70s... or maybe the '80s... (this joke has been repeated numerous times since, including in 50th anniversary special "The Day of the Doctor", where it's implied that some form of "dating protocol" exists). This is compounded by the fact that in a deleted scene from Sarah Jane's first serial, "The Time Warrior", she was scripted to explicitly say she had come from the year 1974. This apparently stemmed from a dispute between the writers of the show as to whether the UNIT years should happen in the present day or slightly in the future (another such continuity snarl line happened in "The Green Death", where one of the Global Chemicals employees tells the Brigadier that they'd recently swapped out their cutting gear for a "thermal lance").
In "Pyramids of Mars", the plot hinges on the idea that the TARDIS' controls are "isomorphic" and can only be manipulated by the Doctor, despite characters like Susan, Jo and Harry having piloted it in previous stories. Robert Holmes later offered the explanation that it was because the Doctor was lying, though Sutekh's ability to read the Doctor's mind makes this unpopular. The same story also has the Doctor make a throwaway reference to having been blamed for causing the Great Fire of London in 1666... something that a Fifth Doctor plot later revolves around. Lying again?
Romana loses 15 years between "The Ribos Operation" (140) and "City of Death" (125). This may have been an intentional Ironic Echo, however, as prior to reducing her age (probably by lying about it), Romana had chided the Doctor about lying about his age.
Dating inconsistencies (see UNIT dating, above) have reemerged in the modern era of the series in several places. Two of particular note:
The 2007 episode "Utopia" establishes that the universe survives for at least 100 trillion years. This is stated directly in dialogue and is one of the major plot points upon which the 2007 season finale was pinned. Fast-forward to the 2015 episode "Hell Bent", in which the Doctor travels to the end of the universe — which is now said to be only a few billion years into the future. Even taking into account the fact that, in the British numbering system, a "billion" is the equivalent to a North American "trillion", it still doesn't work.
Another inconsistency involves companion Clara Oswald, who is said to be 24 when she joins the Doctor in early 2013, but 27 come episodes aired in 2014; a possible workaround occurs in the 2014 episode "In the Forest of the Night" when the Doctor implies that the episode takes place in 2016, which would fix the issue. Clara is Killed Off for Real in the 2015 episode "Face the Raven" which, based upon the 2016 date which was followed by a Christmas special, could not occur earlier than 2017. However, the spin-off series Class is explicitly set in 2016, with dates given on screen, and Clara's death is not only directly referenced, it is indicated (based on comparison to dates given in the series) to have taken place in 2015.
In the revived Doctor Who, the Doctor continually insists that he is 900 years old, which by "The Impossible Astronaut" became 909. This despite the fact that in the original series, the Sixth Doctor also claimed to be 900 years old, and the Seventh said once that he was 953 in "Time and the Rani" (the "expanded universe" novels later had the Eighth Doctor go well past his 1,000th birthday). Given that the remainder of the Seventh Doctor's life and all of the Eighth Doctor's life is lived out after this point, the Ninth and Tenth Doctors must be far older than 900 years old. And to top it all off, he's used the nine hundred figure for his age, how many years he's been time travelling, how much "phone box" travel he's done (which would have to be from the first episode of the original series, when it got stuck like that, and not how long he's used the TARDIS) and how long he's been using "the Doctor" as a nom de plume, four discrete and mutually exclusive things. He may just like the number. Word of God states that he has no way of remembering his exact age, and even if he did, he might be in denial over the big 1-0-0-0. By "Closing Time", he finally pushes past the 1100 mark, however, it's clear from dialogue in "The Impossible Astronaut" that hundreds of years have passed since the previous episode "The God Complex". Subjected to an Internal Retcon in "The Day of the Doctor", where the Doctor admits he doesn't actually know how old he is. He knows he's about 400 years older than his previous incarnation, but that's about it. By the end of Series 9, the Doctor's age becomes a moot point as it now can be measured in the billions.
In "The Girl in the Fireplace", the Doctor and Rose (and Mickey, to a lesser extent) act Out of Character to the way they did in the previous episode, "School Reunion": the Doctor abandons Rose after he'd previously promised her he would never do that; and Rose and Mickey get along swimmingly, even laughing, despite the fact that at the end of the previous episode (which this episode is supposed to take very shortly after) she was unhappy about him joining the TARDIS crew. This is all because Steven Moffat didn't read the script of "School Reunion" before writing "The Girl in the Fireplace". Notably, in the next episode, "Rise of the Cybermen", the dynamic is back to normal.
The planet New Earth is given two contradictory and mutually exclusive locations. In "New Earth", the Doctor claims it's in the galaxy M87. In "Gridlock", he says it's 50,000 light-years from where Old Earth used to be. Even accounting for the fact that both episodes take place five billion years in the future, that's a discrepancy of over fifty million light-years.
"The Impossible Planet"/"The Satan Pit", the Doctor's first encounter with the Ood, is implied by the dates acting captain Zack gives when he logs the deaths of crewmembers to take place in the year 4221. "Planet of the Ood", the Doctor's next encounter, where he and Donna help free the species from slavery, is said to take place in 4126, nearly a hundred years earlier. However, ignoring the dates, "Planet of the Ood" is clearly supposed to take place after "The Impossible Planet"/"The Satan Pit". Space-time warping by the Unrealistic Black Hole involved in the earlier story may provide an explanation, but it's far more likely that someone wasn't paying attention to the dates.
"Orphan 55": Graham (and the audience) see the writing on the sign in the tunnel as Cyrillic, requiring the Doctor to translate. However, it had been previously established that the TARDIS' psychic translation covers writing and Russian, so Graham should have been able to read the sign in the Latin alphabet (which wouldn't have been too much of a problem plot-wise, since the sign has the name of a well-known Russian city written on it). The other possible explanation is that the translation circuits weren't working at their distance from the TARDIS (since the fam was teleported directly to Orphan 55 from the console room), but that would require everyone else at Tranquillity Spa to already be speaking English since the companions have no trouble communicating. Incidentally, the same thing happened decades earlier in the Seventh Doctor episode "The Curse of Fenric," in which Ace was unable to read written Russian.
Earth: Final Conflict can't agree on the nature of the Atavus, the so-called primitive ancestors of the Taelons and the Jaridians. The first episode introducing them has Da'an revert to an atavistic state after being accidentally cut off from the Commonality. He behaves like an animal and acts on instinct with little intelligence. The second appearance has the dying Da'an attempt to merge with a dying Jaridian in order to try to bring back the Atavus. The same episode also claims that the Atavus were an advanced civilization that were artificially separated into two species by a cult of extremists (they became the Taelons, the rest became the Jaridians). The Atavus temporarily created by the merging looks nothing like the animalistic version we're first shown. And season 5 goes in a completely different direction. The Atavus are introduced as a new alien threat. They look a lot more human-like but are changed to be energy vampires, feeding on humans using their energy claws. They don't have the shaqarava organ on their palms (which both previous versions did) and are even said to have ruled over the primitive hominids on Earth before a meteor shower forced them into slumber. There's a reason most fans prefer to treat season 5 as a bad spin-off rather than a true part of the show.
Elementary: Sherlock's original home, 221B Baker Street, appears during visits to London in the Season 2 premiere, Season 6 finale, and Season 7 premiere. In the latter two, it's clearly a completely different building, in a different location, than in the first appearance.
In the first season, Doug Ross mentions at least twice that he has a son. No other details are given about this except the child's age (8) and that he's never even met the boy and doesn't even know his name. This is never mentioned again throughout his time on the series, not even during key storylines when it would make sense — his abusive father resurfacing and later dying, his and paramour Carol's plans to have a baby. What makes this a continuity error is that at one point, when asked if he has any kids, he says, "no". The writers either completely forgot about this or decided to drop plans for any further development.
Med student Gallant mentions having a twin sister with cerebral palsy. When she shows up for a visit, it's multiple sclerosis that she's afflicted with.
Carter is revealed to have had a younger brother who died of leukemia, inspiring him to become a doctor. This is kept consistent. The number of other siblings he has is not. At least one other sibling, a sister, is mentioned a handful of times before Carter officially becomes an only child thanks to his brother's passing.
Malik's surname is given as Williams in a season 1 episode, but is later established as McGrath.
When we are shown the wall with previous ER staff's locker name plates on it in the final season, it includes Malucci's - even though he made a point of taking his name plate away with him when he left.
In a flashback in Forever, Abe gladly goes to fight in Vietnam, but a later episode shows a photo from his days as a student protester. Not unheard of for a young man's view of the war to change after experiencing it, though; in real life many veterans later protested the war.
In the episode with Martin's brother, a backstory about a longstanding family feud is written in to attempt to explain why this character's never even been mentioned before — which might work, if Martin hadn't specifically mentioned in a previous episode, while quelling a fight between Frasier and Niles, that he "never had a brother". It's a stretch, but it could be explained that the feud was bad enough that Martin wouldn't even acknowledge his brother's existence. Except there really isn't a feud between Martin and his brother at all — the brother's wife is mad at Frasier is about the entirety of it. The brothers are even looking forward to chatting, once she (temporarily) forgives Frasier.
There are some problems concerning the ages of Martin and Frasier. It is established that Martin was 21 years old and married to Hester when Frasier was born. There is another episode where Martin recalls being single at 22. In the season 1 episode "I Hate Frasier Crane", Martin mentions that the Weeping Lotus murder took place when Frasier was 12, but it's indicated elsewhere that the case is 20 years old, which creates a discrepancy of about a decade.
In "I Hate Frasier Crane", Martin says that the killer in the Weeping Lotus case tried to stuff the body into a bowling bag. In "Retirement is Murder", he says that the victim was killed at the beach and tried to write a message in the sand, in which case it only makes sense that she was still alive when the killer left the scene.
In Cheers, Frasier said he had no siblings. The first episode of Frasier he meets Niles at the coffee shop and they agree to start talking again. Seems like it's just a Crane family tradition — have a fight, pretend someone doesn't exist until reconciliation. This is lampshaded in "The Show Where Sam Shows Up", where Sam says he thought Frasier was an only child, and that his father was dead and a scientist. Frasier confirms that he just went through a period of pretending his family didn't exist.
Frasier's cat allergy seems to come and go.
In season nine's "Mother Load" it's a plot point that Daphne and Niles can't tell Daphne's mother that they're moving in together because Mrs Moon believes that Daphne's still a virgin. Except two seasons earlier Mrs Moon believed that Daphne was pregnant by her then-fiance Donny.
In an early episode, Joey asks a woman when her birthday is, hoping to hit on her. When his friends object, he claims he is innocently gathering everyone's birthdays. Ross then says "Mine's December...", before Joey cuts him off, intent on talking to the girl. Several seasons later, Joey fills out a medical form for Ross, who is unable to due to a hand injury, and asks Ross when his birthday is. Ross's reply? "October 18th."
Plus there's how old all the Friends are, Season 1 has Monica and Rachel say they're 26, and Ross, Chandler and Joey are 27. (Phoebe is murkier). However by Season 7 Monica and Rachel are 30, and the guys are 31, making them 24 and 25 in Season 1, which is supported by flashbacks of the dates they attended high school/college. It looks like in early seasons the writers planned for the characters to be older, realized it didn't work and lopped a few years off everyone's ages. Or a TV season in our time does not equal a year in show time.
"The One Where Everyone Finds Out" references a Noodle Incident in which Phoebe "made Chandler cry with just her words". Then in a later episode entitled "The One Where Chandler Can't Cry", it's revealed he apparently hasn't cried since he was a child.
In the pilot, everyone talks about Ross's separation as though learning Carol is a lesbian is still news. Ben is born at the end of that season. Season 3's "The One with the Flashback" is set a year before the first episode, and ends with Carol telling Ross she's gay and wants a divorce. So, um, how long was she pregnant, exactly? It's strongly implied at one point — "Carol and I had some good times before she became a lesbian... and once after" — that Ross and Carol conceived Ben after she came out.
In S7, it's revealed that Ross had sex with a cleaning lady in college. Yet, the first two seasons repeatedly point out that, until the series began, Carol was the only woman he ever slept with. (He never specifies when he and Carol first had sex, however, so possibly he slept with the cleaning lady while they were on a break or something.)
In the S6 episode "The One with Rachel's Sister", Monica vehemently denies having a cold and refuses to take any kind of medication for it. Even though, just two seasons earlier (in The One With Joey's New Girlfriend), she has no problem admitting she's sick with one. This doubles as an example of Flanderization.
When did Chandler and Rachel meet you ask? Well, in the pilot Monica introduces them for the first time; nice and simple. But wait! A flashback shows Monica introducing them in a bar a year before the pilot... well, it was only a three second, offhand meeting and they were complete strangers, we'll let it go. But then a S5 flashback shows Chandler visiting Ross and Monica while he was at college and again meeting Rachel... um, what? Ok, ok, they were young, barely spoke to each other and Rachel was totally self absorbed, maybe they forgot. (Even though the meeting included Monica crushing on Chandler and cutting off his toe, pretty memorable stuff, but we'll buy it). Cue a final flashback in Season 10 with Rachel and Chandler talk and make out at a college party with both Ross and Monica present... ok, that they have to have remembered!
Season 10 is notoriously bad for crushing continuity, as it also messes up when Phoebe and Chandler moved in and out. S10 says Phoebe moved out in 1992 before Chandler arrived across the hall. But a flashback from S3 showed Phoebe moving out in 1993 when Chandler had been living across the hall for ages. (Having already gone through one roommate Kip, and it's possible he was Monica's neighbour before Phoebe moved in with her).
The flashback episode during Season 3 established that Joey met the gang and became Chandler's roommate during 1993. Season 5's "The One with All the Thanksgivings" instead says that Joey had known everyone since at least 1992.
Season 7's "the One Where Chandler Hates Dogs" shows that Chandler has a nasty fear of dogs, which he attempted to hide by pretending to be allergic, despite being near one back in Season 4 and neither showing any signs of being afraid of it nor faking an allergy. It also reveals that Ross hates ice cream because it's too cold for his teeth. He was previously seen enjoying an ice cream cone in Season 2's "The One After the Super Bowl", only throwing it out because his former pet monkey Marcel licked it.
In the first episode, Danny tells his mother to return to his father in such a way that implies that his parents are married. Later episodes tell us that Danny's parents have been divorced since childhood.
Steve's last name seems to have changed from Peters (when first introduced) to Hale (in the prom episode). Of course, before that, there was Jesse — who had the last name "Cochran" in Season 1, but "Katsopolis" for the rest of the series. Word of God states that change was deliberate, as John Stamos requested his Greek heritage be reflected in the series.
An early episode shows Jesse attending his high school reunion (with a flashback taking place shortly before graduation). Several seasons later has him say he dropped out of high school (right in the middle of a class, no less) and had been keeping it a secret from everyone else. Even if this did fit continuity, it's questionable how Danny, his long-time brother-in-law, could not have known this.
In early episodes, Jesse was athletic and obsessed with sports. In later episodes, Jesse was a bit out of shape and knew absolutely nothing about sports.
In one episode Joey claims he has never had the chicken pox, however in a later episode his father mentions that he did have it as a little boy.
In the pilot, DJ mentions that Kimmy Gibbler has three sisters. Later on, Kimmy mentions an older brother named Garth, who never appeared. In Fuller House, we meet her never-before-mentioned younger brother, Jimmy.
Gendry makes an offhand comment of his original surname being Rivers - the name given to highborn bastards from the Riverlands. Gendry was a Crownlands bastard, born and raised in Kings Landing. You could argue that he didn't know he was a highborn bastard until he was in the Riverlands but it's an odd choice to make.
The penultimate episode of the series hangs on a plot point that when the bells in Kings Landing ring, it's a signal that the city surrenders. This contradicts Season 2's "Blackwater" when Davos hears the bells ringing and outright says he's never heard them ring as a sign to surrender.
A Season 5 episode flashes back to a prophecy Cersei witnessed as a child. The witch told her she would have three children "with golden crowns and golden shrouds". Cersei actually had four children - the first one was in fact Robert's (the rest were fathered by Jaime) who died young. It's possible the witch just referred to children who would live to their teen years. This also counts as an Adaptation-Induced Plot Hole - in the books Cersei aborted the pregnancy with the first child out of spite.
The Goldbergs has Beverly register Erica at Gimbel's when she gets engaged to Geoff. Another episode from a few years earlier revolved around Gimbel's going out of business.
One of the most famous cases is The Golden Girls. At some point, they hired a new writing team who simply ignored previous continuity in favor of Rule of Funny. Some famous examples:
In one episode, Dorothy mentions that Rose is allergic to cats. However, in a flashback of how Rose and Blanche first meet, Rose mentions that she was thrown out of her apartment because her landlord didn't allow her to keep a cat she found, and was holding at the time. Although, this could be Handwaved with Rose's caring nature, she might put her personal pain aside to help an animal in need. Or that Rose developed the allergy after that incident.
The most famous is Dorothy's children. Dorothy and Stan were married for 38 years, and the show began two years after that. Considering Dorothy had a shotgun wedding, one of her children needs to be at 40 for this to make sense. Although both of her kids were played by multiple actors over the years, neither of them appear to be over 30. Indeed, in his first appearance in season 2, Michael Zbornak is explicitly stated as being 29 years old, while in the season 3 episode where he reveals he's marrying an older woman, he's explicitly stated as being 23 (Lorraine is 44). In his last appearance in season 5, his age is again explicitly given - this time as 30. (Scott Jacoby, the actor who portrayed Michael was born in 1956, making him 30 in his first episode, and 33 in his last appearance.)
Dorothy is stated to be a grandmother early on in the series, having a grandson named Robby. However, neither of Dorothy's children that make an appearance are shown to have children.
Depending on the Writer, Blanche can have between 4 and 6 children. [They eventually tried to knock these together, however; in one instance, she had previously specified she was talking about her four sons (she was offering to give Dorothy one of her sons in exchange for keeping a Mercedes they couldn't afford, saying "I have had four kids, I have never had a Mercedes."). All of her kids were named however: Biff, Doug, Skippy, Matthew, Janet, and Rebecca.]
Rose was adopted as a baby in one ep and at age 8 in another. [Again, they tried to weld these together by saying she was abandoned on the doorstep of the orphanage as a baby and was actually adopted at 8.]
Golden Palace introduces Blanche's mentally handicapped brother, whom she'd never mentioned before, not even when her other brother appeared in The Golden Girls. She handwaves it by saying You Didn't Ask.
The very first episode appears to imply that Chidi is not a native English speaker, or may not even speak it at all. In the afterlife, everyone can communicate with each other while speaking their native tongue, and he says that while Eleanor hears English, he is actually speaking French. However, when the episodes on earth began in the third season, Chidi speaks perfect American-accented English with no hint of an accent despite his native language being French.
The whole mess with Chuck's parentage is one example, as is the fact that most of the time no one can seem to remember that Lily is his adoptive mother, not his stepmother. Safran himself used this trope gratuitously in order to prop the Dan/Blair pairing. For example the sudden references to Dan supposedly supporting Blair in season one by going to an essay contest she partook in. The actual episodes this would have taken place during had Dan disliking Blair to the point that he questions if he could be in a relationship with Serena because she could be friends with somebody like Blair. The numerous interviews Safran gave where he blatantly ignored the show's continuity to prop the pairing certainly did not sit well with the fans.
Dan pretty much proclaims Blair as the love of his life, and the only one he wants. A season later and it's back to Serena and he says the exact same things to Serena that he told Blair.
The reveal that Dan Humphrey is Gossip Girl requires the viewer to ignore or retcon large parts of the series in order for it to make even a little bit of sense.
Green Acres has at least three different flashbacks to Oliver and Lisa's first meeting: one set on an ocean liner, one in which Oliver is a pilot in World War II landing in Hungary, and one in which Lisa is the daughter of the King of Hungary. The last one was Lampshaded by Oliver, who doesn't believe Lisa is related to royalty.
The first Growing PainsReunion Show mentions that the Seavers bought a new house a few blocks from the old one, and has Carol marrying a man with a son. In the second one, Carol and her now differently-surnamed husband are expecting their first child, and the plot revolves around what is supposedly the house from the series, though given the conversion from a stagey sitcom to a realistic TV-movie, you'd be hard pressed to recognize it.
Happy Days: Fonzie recalls having his tonsils removed as a child, yet a later episode has him get a tonsillecomy as an adult.
During the series the layout of the ground floor of the Cunningham home changes, but the exterior shots show the same house. Later Marion complains they have not changed their home in years.
Heroes: The first three seasons/four volumes were meticulously planned out, but the writers on Season Four/Volume Five apparently forgot that one season did not equal one year of real time. This explained why Claire Bennet — a high-school freshman in Volume One — was suddenly starting college, and why Hiro Nakamura was traveling back in time three years to save Charlie — a woman he had met just under a year ago, if you work out the timeline from the first four volumes!
It ran into one with the spin-off film Highlander: Endgame when it had Duncan marrying someone and then making her immortal. Series canon states fairly clearly that he wasn't ever married.
Duncan's history with Xavier St. Cloud. Duncan tells in season one of meeting Xavier during World War I. However, the flashback in season 3's "Finale" shows him meeting Xavier for the first time during the 1600s. There are a few ways to explain why they didn't recognize each other in WW1, but none that can explain why he seemed to lie to Tessa.
Homicide: Life on the Street: In the episode "Stakeout", Lt. Giardello and Pembleton are on a stakeout together, and Giardello is upset by Pembleton's constant smoking, saying that he's never smoked. In earlier episodes, Giardello was frequently seen smoking cigars.
Robert Frobisher-Smythe was dead, and this was proven due to Nina seeing his ghost. In season three, he was suddenly alive, albeit in a hundred-year long coma, and acted as the season's villain.
In one episode of season two, Alfie is revealed to be claustrophobic after an incident in the tunnels. However, in season one, he was able to hide in a cupboard in the shelter to hide from the secret society, and spend the night locked in a sarcophagus.
The show made a glaring error with the first-season episode "The Sweet Taste of Liberty" and the fourth-season episode "The Fight". In "The Sweet Taste of Liberty", Marshall is relieved that he doesn't have to fight a man he thought was hitting on Lily because he's never been in a fight before. However, in "The Fight", Marshall is able to take out a huge, violent man with one punch, and reveals that he used to have Fight Club-style brawls with his brothers.
The first time they reveal Lily's Stalker with a Crush Scooter's real name, it's Bill. The second time they reveal it, it's Jeff.
In an early episode, Carly never takes baths because she hates sitting in her own wet dirt. Come iToe Fatcakes, her entire B-plot revolves around her having a bath and somehow getting stuck in it.
Sam has to endure a Carly makeover to become "girlier" to impress a boy she likes. A few seasons later, Sam is revealed to have been a pageant girl for a long time, and there's no way she would've needed Carly's help to change to be a little girlier.
According to iCarly (2021) episode "IM Cursed", Carly's birthday is on July 24th. Original series episode "iGot a Hot Room" showed her in school on her birthday. Most American public schools let out for summer vacation in late May or early-to-mid June and don't resume until August or September. This is partially due to a retcon, as Carly's birthday was previously on January 14th (as listed on iCarly.com) and the date was later changed to take place closer to the airdate of "iGot a Hot Room" (July 30th 2010).
It's established early on that genies can't be photographed. And then along comes a plot when there's a small scandal because Jeannie's been mistaken for someone else, and a paparazzi shot of her and Tony gets into the local paper. And then they go back in the wedding episode, where they have to have a plastic stand-in dummy switch with Jeannie whenever a camera is focused on them, and they end up having to steal the movie that was made of the wedding. Make up your minds!
It's spelled out in a relatively early that Jeannie would lose her powers should she marry Tony, which almost causes him to marry her on the spot, until he learns that any children they have might have genie powers. Then they get married in the final season. Surprise surprise, she doesn't lose her powers.
Jeannie seemed to personally know a lot of historical figures that were around in the 2000 years that she was supposed to be trapped in her bottle...
Originally, Jeannie was a human girl, until the Blue Djinn turned her into a genie and trapped her in a bottle after she refused to marry him. Later episodes not only flat out state that she was born a genie, but her other genie relatives often come to visit.
I Love Lucy gives Ethel several different middle names, and Ricky two different first names.
Interview with the Vampire (2022): In "A Vile Hunger for Your Hammering Heart", the gravestone commissioned by his sister Grace establishes that Louis de Pointe du Lac's birth date is Oct. 4, 1877 (which must be the correct year because he was 33 years old when he was turned into a vampire in late 1910, plus Daniel says that Louis is 144 in June 2022), yet in "The Thing Lay Still", he informs several would-be victims that he was born in 1878.
On The Jeffersons, in some episodes, George Jefferson states that he is an only child, despite George Jefferson's brother Henry Jefferson being mentioned in early episodes and appearing on All in the Family. Henry's son Raymond Jefferson appears in season 5, but Henry Jefferson never appears.
Justified: In early seasons several references were made to Dewey Crowe's cousin Dale Crowe Jr., whom Raylan had arrested for alligator poaching and put in Stark Penitentiary. In Season 5 we meet his cousin Daryl Crowe Jr., whom Raylan arrested for alligator poaching and put in Stark. Needless to say, it seems the writers simply forgot the name they'd originally used.
Kaamelott: Arthur offers an expensive dagger to Madenn early on in "La Coccinelle de Madenn", claiming he killed an Ostrogoth chief with it. We see the actual event in the prequel season Livre VI, but the curved knife Arthur uses to (allegedly) cut the throat of the Ostrogoth chief looks nothing like the aforementioned dagger.
LazyTown: Between the first and second episodes. The former implies Sportacus is a newcomer: the previous hero wore a "9" whereas he wears a "10"; Sportacus says he's heard of LazyTown but still had to research it; Robbie Rotten shouts "Another one?!" when he first sees him; and Sportacus formally introduces himself to the townsfolk at the end. The latter, however, states that Sportacus taught everyone to play baseball the year before.
In Lois & Clark, Lois' father was first portrayed as a serious man in season 1. In season 3 and 4, he was played by a different actor and portrayed as a goofy inventor.
For most of the series, it's made clear that Hawkeye was an only child and that his mother died when he was ten. In several early episodes, Hawkeye mentions having a sister and that his mother is still alive.
Henry Blake's wife was named Lorraine, but an early episode has him on the phone addressing her as "Mildred". (Then again, he did have a concussion — he was also trying to talk to said wife on a disconnected phone and saying he was going to be late getting home from work, so him calling his wife by the wrong name isn't out of the question.)
Henry's son was supposedly born in the Season 1 finale, but in the Season 3 finale, he's old enough to play the trombone. Even if we assume the passage of time within the show was the same as the time between the episodes in question, his son should only be two years old.
Col. Potter once gave his age as 62, but in his first appearance, he said he lied about his age and joined the army during World War I at 15, which would make him around 50 at the time he arrived at the 4077th.
Margaret Houlihan once told Col. Blake, "You look like my father did right before he died." Her father, 'Howitzer Al' Houlihan, would later visit the 4077th.
In one episode, Frank was addressed as "Franklin D. Burns" (consistent with the novel, which listed his name as Franklin Delano Burns) but a later episode said his middle name was Marion.
Despite the Korean War lasting less than four years, the show has five Christmas episodes.
The general timeline of the series is a full-on Continuity Snarl. Perhaps the most blatant example is that the Season 4 premiere gives Potter's date of arrival at the 4077th as September 1952, but a later episode depicts him being with the unit for New Year's Day 1951, almost two years earlier.
On The Mary Tyler Moore Show, Rhoda's number of siblings seem to change every so often, leading up to her spin-off where she only has one sister, Brenda. (not helping is the fact that on TMTMS, we do see Rhoda's sister...only it's a DIFFERENT one named Debbie who gets married when Mary is visiting in New York. We never hear about her or her family again.)
Midnight Caller: Most of the second-season episode "Someone to Love" consists of a flashback to the year before, but Jack and Devon still have their second-season haircuts.
In "Arrested", several episodes into Modern Family's fourth season, Haley is expelled from college and returns home. She's curiously absent from the next episode, "Mistery Date", and the only mention of her is when her mother says she gets emails from Haley about her nails, implying Haley's still at college.
In one episode, Lieutenant Disher mentions that he doesn't have any uncles. A few seasons later, an episode revolves around him inheriting his uncle's farm.
In season 3, we meet Joe Christi, a former cop who tells Sharona that he was present when Monk got the call about his wife's death. The series finale depicts this scene, and there's no Joe to be found.
Mork & Mindy: In a season 1 episode, while aged down to a toddler, Mork shows Mindy his bellybutton. Later episodes establish that as a test-tube baby, he doesn't have a bellybutton. Until one is created when he lays an egg through his stomach... It Makes Sense in Context.
Murder, She Wrote: In the season 2 episode "Joshua Peabody Died Here ... Possibly", Doc Hazlitt is adamant that there is no evidence Cabot Cove's legendary Revolutionary War hero Joshua Peabody even existed, and nothing in the episode changes his mind. He reiterates this position later in the season in "Keep the Home Fries Burning", set at a restaurant called the Joshua Peabody Inn. In the Season 11 episode "To Kill a Legend", however, nobody seems to doubt that Peabody existed. And why would they, when he has descendants living in the town? Instead the controversy is over whether he was really as heroic as believed, with Doc as one of the leading supporters of Peabody's legacy.
The Hickey brothers didn't know Joy until Earl married her and Catalina until after Earl's karmic revelation. All the flashbacks make you wonder a little why they didn't know Joy most of their lives and Catalina during the six years she had immigrated to America, as both seemed to be regulars at the Crab Shack. Camden is a small town after all.
Speaking of Catalina, she told Earl in the early episode "Teacher Earl" that she only learned English a year ago. Nearly all flashbacks feature her speaking fluent English, and the ones that don't take place either before or just after she immigrated to America. Additionally, in "South of the Border", her uncle and brother can speak fluent English even though they've never been to America, making it less likely that Catalina wouldn't know at least some English before immigrating.
Like Catalina, Nescobar A-Lop-Lop, who was being taught English by Earl in "Teacher Earl", is speaking decent English in all flashbacks
They established that Earl married Joy in November (six months pregnant with her son Dodge) and they had a Y2K adventure for their first New Years together. The last episode showed that Dodge was conceived on Halloween.
In "Made a Lady Think I Was God", Darnell says that Mr. Turtle doesn't have a first name (with Randy naming him "Randy"). In "Got the Babysitter Pregnant", Darnell buries a turtle he thinks is Mr. Turtle (Joy lost the real Mr. Turtle and got a replacement turtle that died) and the headstone reads "Mr. Sydney Turtle". It's possible that Darnell gave him a first name later.
In "Barn Burner", Randy suggests that he and Darnell from a moped gang called Salt and Pepper, because they both like salt and pepper on their French fries. In later episode "Little Bad Voodoo Brother", Randy says that he can't taste salt due to ingesting bleach as a result of Earl's mean-spirited pranks in their youth.
In "Cost Dad the Election", Earl says he's allergic to cats. In "Larceny of a Kitty Cat", it's Randy who is allergic to cats.
In "Our 'Cops' is On!", the first episode of COPS filmed in Camden County was said to have taken place in 2003. In "Our Other Cops is on!", the second episode of COPS filmed in Camden is said to have taken place on the first Independence Day after 9/11, placing it in 2002 and it contains references to the previous episode of COPS, so it couldn't have been filmed before the other episode.
While NCIS is usually fairly good about this for a long-running police procedural, there are a few occurrences, such as in "Frame Up", where Gibbs states about Tony's service and arrest record "Eight years, three different forces. There's a lot of people who hate you." while in fact Tony has only served in two 'forces' - the police department and NCIS. This could be handwaved by saying that Gibbs was referring to the three different police departments Tony has served in, but the context would suggest otherwise.
The Odd Couple did multiple episodes showing how Felix and Oscar "first met." Also, one episode establishes that one of them didn't have any wedding photos; in another episode, he is seen looking at his wedding photos.
Odd Squad messes up its own continuity so frequently that fans have taken to creating a series timeline based on what has been revealed. Some of the most infamous examples:
The events surrounding Delivery Debbie and Delivery Doug are rather muddled. They were introduced as being rivals to each other with competing businesses before "Mystic Egg Pizza" had them eventually burying the hatchet and combining forces to open a restaurant that serves egg salad pizza, which is never brought up again in subsequent episodes. "Disorder in the Court" implies that the duo split up, revealing that Debbie is still running her pizza business, while "O is For Opposite" showed Doug moving his own business's operations from his mother's basement to an alleyway in town. "Safe House in the Woods" depicted them as rivals again (albeit on a friendlier scale than "Mystic Egg Pizza"), while "Teach a Man to Ice Fish" reveals that Doug has opened another egg salad restaurant in the Arctic.
A couple in "Switch Your Partner Round and Round".
It's revealed that Oprah didn't pair up Olive and Otto initially, cycling through numerous different pairings before settling on them being together. However, "Training Day" showed her presumably picking Otto off the bat for Olive to be paired up with following the firing of Odd Todd. Justified by the fact that either the Director knew she was going to have to fire Odd Todd eventually and was hesitant about pairing Otto with Olive, or Otto was only one of her options alongside Oksana, Oren and Orchid.
One of the stills shown during the activation of the What-It-Would-Have-Been-Like-inator helmets is from "My Better Half", depicting Oren getting half of his body removed by Symmetric Al. This is despite the fact that his name is not symmetrical, unlike Otto's. The same also applies to Orchid, as another still shows her with half of her body taken despite her name not being symmetrical.
"Oscar of All Trades" has Oscar revealing his backstory to Olive about how he started the Science department in Precinct 13579 when he was 11 years old. "Rise of the Hydraclops" previously depicted him in Scientist attire at 5 years old.
The episode "Disorder in the Court" surrounds Odd Todd getting Olive kicked off of Odd Squad via Frame-Up because he's mad at her for getting him fired from the organization. In reality, Olive never conspired against his firing, and in fact was very submissive when he was going through his Face–Heel Turn due to her shy nature.
In spite of being a direct sequel to the Season 1 finale, "First Day" appears to take place in summertime (or at least in a warmer month), whereas "O is Not For Over" took place in the wintertime. Given that this is primarily a live-action show with different filming times, though, this has some justification.
"Villains in Need Are Villains Indeed" depicts Precinct 13579's Headquarters as being situated aboveground, when numerous past episodes have shown that it's an Elaborate Underground Base.
"Portalandia" has Omar explaining that no one in the Mobile Unit can speak Japanese. Later on, he says that the slogan of The Portal Master store rhymes in Japanese, and Orla reads aloud a sign written in Japanese that tells her and Omar where they need to ago (although her English translation is incorrect).
Opal explaining that the Mobile Unit has gone paperless in "Raising the Bar" would be a neat example of invokedTechnology Marches On...if the episode hadn't shown her working with paper just a few minutes beforehand.
The B-plot of "Odd Squad in the Shadows" is about whom is the leader of the Mobile Unit, with all four agents vying for the position. Opal has no need to, however — she's already the de facto leader in a recognized role.
In "Down the Tubes", O'Shaughnessy tells Orla that agents cannot more than four tube rides a day lest they experience exhaustion and drowsiness. This is despite the fact that agents have gone through the tubes multiple times without getting tired and Oswald only went through two tube rides, not four, before becoming exhausted. note Since he's depicted as being weaker than his teammates to an extent, this may be justified, but it doesn't quite explain how those like Oscar — the weakest out of the Season 1 cast before Character Development kicked in — can partake in Tube Travel three times without any ill effects.
From "Odd Off The Press":
Orpita's Agent Report is referred to as a book report when it wasn't called that in "It's Not Easy Being Chill".
Strength is among one of the things tested as part of Orpita's interview to find a substitute Big O. Since "O is Not For Over" previously established that strength training is a required element for newly-promoted Directors, testing the candidates' strength doesn't do much in terms of qualification.
The second half of "Double O Trouble" opens up with a Chicago police officer ticketing the Mobile Unit van for illegal parking. The kicker? There Are No Police — Odd Squad takes up that role instead. "The Confalones" was the only previous episode to mention police as an instance of Early-Installment Weirdness.
"Welcome to Odd Squad" has a whole lot of continuity errors. Where to begin...
The names of departments. Creature Care is referred to simply as "Creatures", the Food and Beverage department is referred to as "Kitchen Services", the Task Force department is referred to as "Internal Investigations" note It was also referred to as such in the Odd Squad Agent's Handbook, but that is considered Loose Canon, Maintenance/Transportation is just referred to as "Tube Lobby Operators" with no mention of the Maintenance side, and Athletics and Conflict Resolution is just referred to as "Athletics" while dropping the Conflict Resolution part of the department entirely.
The commercial neglects to mention that there are over twenty different departments at Odd Squad, far more than what is actually represented.
It also implies that Odd Squad Directors don't have their own department, when on the contrary, Management is their department.
The Grand Finale "Odd Together Now" is chock-full of more continuity errors than you can shake a stick at.
Despite having been fired by Orpita and surrendering his badge in the previous episode, Olando is still shown wearing his badge and works as a juice inspector in one of the Big Offices. Likewise, Osmerelda poses the idea of consulting him for help on the Golden Sundial even though he was previously antagonistic towards Odd Squad, showing little regard for the Mobile Unit agents' health and safety. The end of the episode also has Olando deciding to stay in the present time and declaring that he'll get a new agent suit, even though Orpita is never shown rehiring him back onto Odd Squad at any point.
The Mobile Unit seeks to destroy the sundial even though Olando previously stated that destroying it would bring a massive timetastrophe that could possibly alter the universe for the worse. Even Olando himself is on board with the idea — and he's definitely not regarded as an agent with a bad memory.
Olando is a recognized and respected figure by both Logan the Ogre and Wanda the Wizardess, although they only recognize him for one feat. Although it's justified since Wanda and Logan could both have the ability to live for a long time and we never hear about Olando's life prior to becoming an Odd Squad Protector, the Mobile Unit and their Rogues Gallery just learned of his existence not too long ago, and it seems quite farfetched that Wanda and Logan, of all people, would know about him and his brave deed.
A Featherite is among the group of villains who plan to break into the Big Office. In the Featherites' debut episode, they were introduced as being, at best, on neutral and friendly terms with Odd Squad, and filling the role of an ambassador of sorts to the organization.
Meredith went from having two kids to having one, and from being an accountant to a supplier relations rep.
In one episode, Michael wants to throw a birthday party and asks Pam when the next birthday in the office is. She tells him the next birthday is Meredith's, which is "next month." In another episode, Jim says that it's "birthday month" and that "Kelly's was last week, Creed's is today, Oscar's is next week, and Meredith's is at the end of the month."
In one episode, Jim says that he's had a crush on Pam since her first day at Dunder-Mifflin. In another, he says he's had a crush on her since she showed him to his desk on his first day. Obviously, that only makes sense if they both started on the same day, but it seems odd that he wouldn't refer to it as "our first day" if that were the case. Greg Daniels says that this is the writers being forgetful. He also says that he personally prefers the story Jim tells of his "worst first date", or the first day Pam started.
In Season 4, Andy introduces his parents as "Andrew and Ellen Bernard." However, in Season 6 he mentions that his father's name is Walter (explaining that his own original birth name was Walter Jr. before that name was given to his "more worthy" younger brother). In Season 8, his father's full name is established as Walter Baines Bernard Sr (in this episode both parents are also played by completely different-looking actors from those shown in Season 4).
In the Pilot of Once Upon a Time, Snow White says that the Evil Queen made her eat a poison apple because Snow was prettier than her, much like the original Snow White story. Later on in the series, we learn that her motive was a great deal more complicated. (Possibly justified in that the true reason might still have been too devastatingly personal to her to discuss with someone else.)
Harold is mentioned to have created a false identity to attend MIT in 1976, and to have hacked the Arpanet with a home-built computer in high school. A flashback in the third season shows a young Harold hacking the Arpanet while still living at home in Iowa - in 1981. Though he was portrayed as living at home because he was taking care of his ailing father, so both could be true.
Fusco was caught on camera destroying the files of an undercover police officer. This was then used to blackmail him, despite the fact that in the episode, he made a point of covering the camera before he began.
In the first season of Powers, Christian Walker is depicted as a young man discovering his powers in 1994, stopping Wolfe in the Sanction Lounge, but in the second season, he's noticeably older in 1998 and losing his powers in 2000, despite the first season stating that ten years passed between Wolfe being defeated in 1994 and his first escape from The Shaft, which would put Walker losing his powers in 2004.
Radio Enfer: A Season 5 episode has Maria trying to help Dominique get the attention of some guy named Rénald Langlois. At one point, Maria says that a future first boyfriend is a big step and that Dominique shouldn't panic. However, by that point in the series, the latter already dated characters such as Léo, Vincent, as well as Vincent's brother Cédric.
Robin of Locksley and Guy of Gisborne meet for what is clearly the first time in the pilot episode. In season three the writers try to pull off a massive Retcon with a Whole Episode Flashback that demonstrates that the two were young boys together. They might have gotten away with it if the flashback hadn't also included some fairly dramatic revelations: Guy's mother and Robin's father were engaged, that Robin lets Guy take the blame for a prank that nearly gets him executed, and that their parents end up dying together in a fire. The fact that neither Robin or Guy has ever mentioned any of this before is more than a little absurd.
Guy wrongly believes that he was responsible for the fire that killed his parents, even saying that it's haunted him throughout his lifetime. However, he didn't seem particularly "haunted" when he set fire to Marian's house back in season two.
Round the Twist: Between seasons two and three, the main characters actually get younger, to the point where two of the kids are one year younger than when they moved into town. Then there's Nell, who was "never married" early on, and in another episode time travel involves meeting her future husband who was manning an observation post during World War II.
It isn't clearly defined which year the first season is set, but as San Francisco Pride Week and Independence Day are significant events at the beginning and end of the season, the timing is definitely late June to early July. But at the end of the second episode (still late June in the show's context) a TIME Magazine cover for July 28, 2014 is clearly visible, as is a Sedona Magazine cover for April of the same year.
Despite the implication that the year is 2014 in the show, a date and day shown on Kala's phone in the next episode is June 25th, Thursday. June 25th was not a Thursday in 2014. It was in 2015, though, which raises the question; why did the convenience store Will went to have year old magazine issues on its shelves?
Sesame Street: Episode 4059 has Curly Bear eating a banana. In a later episode, Baby Bear says she never ate a banana before.
Sex and the City: Early in Season 6, Carrie is shopping with Samantha and tells her, "I don't buy furry shoes;" Carrie bought near-identical shoes (maxing out her credit card and allowing a friend to pay for them, no less) in Season 1.
Sneaky Pete: One episode has Marius pretending to be a taxidermy expert and referring to a stuffed American buffalo as a bison. In the next episode, he calls it a buffalo and is corrected by someone else that it's actually a bison. Marius acts like he didn't know this already.
Soap: In the very first episode, Chester claims to be diabetic when Benson brings him coffee with sugar. A season or so later, trying to justify his sex addiction, he tells his wife, "If I had diabetes, you couldn't blame me for not being able to have sugar."
So Weird: In season 2, Fiona has a pet cat, and has had it for some time. A long-haired cat at that. In season 3, her mother is severely allergic to cats and can't stand to be near one. (Though it is possible to develop a cat allergy...)
Supergirl (2015) can't keep a straight timeline or even idea as to how the Luthor-Superman rivalry played out before the series began. Early on, Luthor's arrest is treated as something relatively recent, yet the flashbacks to Kara's childhood one episode mention Superman as having already arrested him. Jimmy Olsen states early on that Superman and Luthor were friends for some time before Superman accepted Lex had gone bad, but this is never alluded to again, even when Jimmy recollects how Luthor tortured him the first time that they met. Season 4, in a flashback dated five years ago, shows Luthor turn the sun red and get arrested for it, in what is implied to have been their most recent battle, but then season 5 shows another flashback, also dated 'five years ago' where Luthor first explains his hatred of Superman to Lena, and states that they've just made first contact with an alien (which also contradicts how Superman has clearly been active on Earth since at least when Kara landed more than a decade before)
Stranger Things: Will's birthday was established to be March 22nd in Season 2, but Season 4 later has an episode take place on March 22nd with no mention of it being Will's birthday, which the Duffers admitted was because they forgot about it. Given that Will calls out Mike for the ways he feels ignored by him that very day, it would probably have come up if one of them was forgetting his birthday.
In an episode of The Suite Life of Zack & Cody, London is shown to be very competent in physical sports. In an episode of The Suite Life on Deck, she needs Zack's help. Did she leave her muscles in Boston?
In Tensou Sentai Goseiger, Agri gets upset at the idea of Moune having a boyfriend, yet in a later episode the team explicitly does not know what romantic love is.
Tokumei Sentai Go Busters's early episodes emphasised that Yoko, who had come to EMC at age three, knew very little of the outside world and had never had a chance to spend time around civilians. This is contradicted in a later episode which shows that she attended middle school.
There is no consistency in terms of what's the name of Grumm's master.First, Gruumm talks to "The Magnificence". Then the creature called The Magnificence is being called Omni as if he had been all along, and "The Magnificence" is something else (the body for Omni, which many of the crimes were about completing, as it turns out near the end). Then the whole vessel is being called Omni.
"Troobian" is the name of Grumm's empire, which seems to consist only of two or three guys of different races, and tons of robots Broodwing sells to anyone who can pay. It is later used to mean "only" the robots, whether used by Gruumm-affiliated villains or not. By the end, fans were left confused,wondering what is a Troobian.
There are a few instances of events or terms that happened in Tokusou Sentai Dekaranger but not S.P.D. being referred as if they happened. A good example is when Sky-as-the-criminal worried that he'd be "deleted on sight."(In Deka, the Monster of the Week are destroyed or "deleted", which didn't carry over into S.P.D).
The entire season made it clear that Doggie is The Last Sirian, which gets thrown out of the window in the finale when we learn of Isinia, which raises the question of whether more Sirians survived as Troobian slaves . Even worse, we learn that she is a captive of Omni, not Gruumm, as would be expected, considering the rivalry Gruumm and Doggie that happened over the course of the entire season.
The episode "wormhole" seems unclear in terms of continuity, since Morgana is suddenly back in her child body(which would not happen for a few more episodes) as Mora, which is problematic, since after Morgana returns as Mora in the final episodes she's almost immediately brainwashed by Omni.
A notable example in the episode "One Fine day", where the rangers spots Norg and decide to chase after him, thinking its big foot and they will be famous if they catch him. Problem is:
They have seen Norg before, With mack even speaking to him in a previous episode.
The rangers actually went to a talk show before and are already famous In-story by that point.
One notable error that pops up often between Power ranger seasons is about the rangers and if the public knows them or not. Since it has been made clear that all seasons are in the same continuity (excluding RPM and Dino Charge), it becomes nonsensical in how the new rangers have no idea about the previous teams or even heard of them. For example, Ninja Steel and Megaforce seasons: In the former, the group acts as if they have never heard of power rangers and are clueless, while the aliens they fight seem to know what they're dealing with. It gets very weird when Hayley has to piece together the word "'mega'... zord?" out of Buffy Speak. Even weirder as other times they have hints that they do know some things, like Hayley having no problem accepting alien monsters exist in the second episode, and even asking for clarification on the type of monster, which only really makes sense in that context. Meanwhile, in Megaforce, the season seems to treat the former seasons as a urban legend at best, which, as people like Linkara noted , makes absolutely no sense by that point, with seasons like Lightspeed Rescue(where the Rangers were a public rescue force and had no secret identity at all) and In Space(Where the final two episodes involved a huge invasion across the universe and the rangers being forced to reveal their secret identities to the public).
In the pilot episode, Dean tells Sam he hasn't spoken to Sam in two years. Since Sam is in his senior year at Stanford, this suggests the boys had contact while he was at college. However, later episodes seem to indicate that the boys have been separated since Sam left home to go to school. It's possible there was some phone contact or something, but this would have been significant and is never addressed. It's more likely a mistake that was retconned.
Sometime in season 8 or 9, the writers somehow got the idea that Reapers were a type of angel, even though they had always been treated as two entirely unrelated species prior to this and it caused numerous problems with previous plots involving Reapers. Later seasons rectify this by going back to treating them as separate.
All of Season 5 (it was a major plot point/parallel) mentioned that Michael was older than Lucifer. In Seasons 11 and 12, Lucifer is referred to as the "first son" and Lucifer calls Michael his little brother.
Terminator: The Sarah Connor Chronicles has a serious timeline inconsistency surrounding the episode "Alpine Fields". The episode has two separate time-frames, one featuring Derek Rees attempting to deliver a wounded pregnant woman's baby in what is implied to be the episode's "present", and the other with Sarah trying to protect the same woman and her family from Terminators during an earlier stage of her pregnancy. The problem is that the woman isn't visibly pregnant at all in the earlier time-frame, suggesting that months have passed between the two sets of scenes. However, the events of the entire two seasons of the show don't seem to last that length of time, and a scene in the later episode "Ourselves Alone", involving the question of whether Sarah has a firearms licence, suggests that the entire show up to that point has taken place in a time period of less than thirty days!
In the first episode, we learn that Eric and Donna have lived next door at least since age 4. In a later season, a flashback shows their first meeting, at age 8. Jackie is established in the first season as a sophomore, and the other characters as juniors in 1976. Five years later the characters (except Jackie) graduate at the same time. Three years after that, they all say goodbye to the 70's on New Years Eve, 1979. If not for the Halloween/Thanksgiving/Christmas episodes, you could say that each season represents less than one year of the characters' lives...
In the second episode, we meet Donna's sister Tina, who is never seen or mentioned again, save for one joke at the end of an episode that, while asking questions in the style of Soap, the narrator asks "What ever happened to Midge's other daughter Tina?"
In "Robarazzi", Jade mentions having had tuna fish for lunch. Later, in "The Wood", she says she hates tuna fish. Tuna fish did prevent her from getting laid, though, so it's possible she changed her mind.
In the episode "The Breakfast Bunch", Tori says she's never had detention before. However, she got two weeks of detention in the season one episode "Stage Fighting".
In the original run of WKRP in Cincinnati Herb Tarlek acknowledges his alcoholism. In the syndicated New WKRP, he was a social drinker again.
The Wire: So minor that it's understandable the writers missed it, but in the Western District there's a photograph of Bill Rawls in a Major's uniform next to Major Colvin's, indicating that he's Colvin's predecessor as commander of that district. However, in The Wire Prequels, Rawls is shown already leading the Homicide CID unit downtown... as a Lieutenant.
In the episode "Art Teacher", Mr. Laritate is surprised that his phone gets text messages when a teacher "texted in her resignation." In a later episode, he apparently still doesn't know what a text message is.
In the episode "Monster Hunter", Jerry says that he remembers when Justin was still turning bricks into rabbits and Justin nostalgically responds "Edgebono Utoosis". However, in "The Crazy 10 Minute Sale", it's shown that "Edgebono Utoosis" is a spell to create a duplicate of whatever it's cast on. Not to mention Justin never turned a brick into anything. He duplicated a rabbit, and in a totally different episode, Alex turned a dove into a brick.
An episode had Alex say that every wizard learns the zombie language when they're little, but an earlier episode established she didn't know she was a wizard when she was little.
In "Make it Happen", Jerry says his father was a rodeo clown, but in "Rock Around the Clock", Grandpa Russo clearly owns the sandwich shop.
The pilot establishes that Paradise Island, in 1942, is a Hidden Elf Village of Action Girls who had never seen a man in a thousand years. Princess Diana is elected The Champion to travel to Man's world. She is the first Amazon to leave Paradise Island in a thousand years. Then the first season happens in The '40s. However...
In the second season episode "The Man Who Made Volcanoes", her first year back in Man's world since World War II, (The '70s), the villainous Arthur Chapman says Diana had foiled a scheme of his a few years earlier.
In the third season episode "Diana's Disappearing Act", Cagliostro claims that Wonder Woman has stopped all his lineage's plans since the original Cagliostro (born in the 18th century) and...
In "Screaming Javelins" Diana remembers having met Napoléon Bonaparte, implying not only that she was in Europe those years, but that she was already doing her superhero job. She had also supposedly foiled a scheme of Mariposa's some years earlier but this is somewhat less problematic as she had actually been back a while by this point.
In Season 1, Mulder describes the abduction of his sister, saying he couldn't see what was happening due to paralysis which prevented him from turning his head. In the season 2 premiere, the abduction is shown in a flashback, and young Fox is looking right at her as she floats out the window.
Mulder claims to be red-green colorblind in an early episode, yet doesn't seem to have any trouble noticing what's odd about the green blood shed by an alien bounty hunter in a later season.
One of the very first things ever stated about Mulder in the series is that he's a psychologist, and it remained a consistent detail throughout. However, in a later episode, he makes an offhanded comment that he's not a psychologist.
Young Blades: When Jacqueline meets The Great D'Artagnan in "Secrets of the Father", she excitedly goes on about how she used to swordfight with her brother while pretending to be The Great D'Artagnan. D'Artagnan (his son) clearly hears this and doesn't seem to be surprised or care. But several episodes later, in "Secrets", Jacqueline is suddenly very embarrassed about pretending to be The Great D'Artagnan and doesn't want D'Artagnan to know about it. When he overhears, he teases her about it. Neither of them seem to recall him finding out about it before.
. In "Gridlock", he says it's 50,000 light-years from where Old Earth used to be. Even accounting for the fact that both episodes take place five billion years in the future, that's a discrepancy of over fifty million light-years.