Trivia / Harry Potter and the Half-Blood Prince

• Ability over Appearance: Jim Broadbent's Slughorn is different from how the books describe him - short, incredibly stout and bald, and with a walrus-like moustache - but he displays the shrewd opportunistic yet friendly quality perfectly.
• Beam Me Up, Scotty!: Snape killing Dumbledore doesn't happen on page 606, despite what Memetic Mutation shows.
• Billing Displacement: As has become a common trend of the films by now. The veteran actors are billed in the main credits as usual. Most glaringly, Timothy Spall is listed as a major star despite having only six seconds of screen time.
• California Doubling: While the previous films had plenty of England doubling for Scotland, this is the first and only time that the series filmed anything outside of the U.K. entirely. The exteriors for the cave (which is Cornwall in the book) were filmed at the Cliffs of Moher in Ireland, and the exterior scenes of the Hogwarts Express traveling through a snowy landscape were shot in Norway.
• Cast the Runner-Up: Helen McCrory who was initially cast as Bellatrix Lestrange, but dropped out after due to her pregnancy and being replaced by Helena Bonham Carter, was cast as Narcissa Malfoy, Bellatrix's sister and Draco's mother, once her maternity leave was over.
• Creator Backlash:
  • Daniel Radcliffe views this as his weakest performance in the series. He was also having troubles with alcohol at the time, which likely contributed to this.
  • In a note that Alan Rickman wrote to himself during the production of this film, and which was released to the public years later, the actor declares frustration with David Yates, believing that the director "has decided that this is not important in the scheme of things i.e. teen audience appeal."
• Hey, It's That Place!: The exterior of the cave was filmed at the Cliffs of Moher in Ireland. To fans of The Princess Bride, those are the Cliffs of Insanity.
• Hide Your Pregnancy: Helena Bonham Carter (Bellatrix Lestrange) was pretty noticeably pregnant in the film. The scene where she and Narcissa visit Snape has a couple of shots where her belly is very poorly hidden, even wearing a flowy black dress. She spends most of the scene in the background and/or hiding behind the furniture and Snape and Narcissa. It's better hidden in some of the other scenes.
• Orphaned Reference:
  • In the attack on the Burrow, Ginny inexplicably does nothing once Fenrir Greyback shows up. As shown in the trailer, he disarmed her from afar. Ginny can be seen picking up her wand as soon as Lupin and Tonks get there too.
  • The twins Flora and Hestia Carrow are given a lot of attention during the Slug Club scenes. This is a holdover from an earlier draft when Harry would realise that the Vanishing Cabinet had a second one.
• The Other Darrin:
  • Frank Dillane replaces Christian Coulson, who played Voldemort's teenage self in the second movie. This was due to Coulson now being viewed as too old for the part, despite him having been so in the first place (23 playing a 16-year-old). Oddly enough, this recasting carried over to the Japanese dub, wherein Jun Fukuyama replaced Akira Ishida as the character's voice.
  • Minor example. Lavender Brown had been played by background extras in previous films. Here when she has an actual role, she's played by Jessie Cave - and given a Race Lift (the previous two actresses were both black).
• Real-Life Relative: Tom Riddle's eleven-year-old self is played by Ralph Fiennes's nephew Hero Fiennes Tiffin. Word of God is that his resemblance to Ralph and his "dark, haunted quality" played a factor in his casting.
• Release Date Change: The film was originally scheduled for a November 21, 2008 release, but it was later delayed until July 15, 2009. The reason for this is that the 2007-08 writers' strike had left Warner Bros. without a tentpole release for '09, and Warners had already had a tentpole release in '08 with The Dark Knight. As a result of this, Half-Blood Prince didn't come out until over a year after it had actually been filmed, by which time they were already well into the filming for Deathly Hallows. Meanwhile, Summit Entertainment decided to move a little film of theirs called Twilight into the vacant November 21, 2008 slot.
• What Could Have Been: Has its own page here.

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