The first time the Fox and Kristofferson have to dig in order to escape being dug out, Mr. Fox tries to apologize to Ash for taking Kristofferson along on a heist instead him, but he ends up mainly talking about how great Kristofferson was at it, which of course offends Ash further. So he's digging himself deeper while literally digging himself deeper.
Mrs Fox warns Mr Fox that "this story's too predictable", which is a sign that the film will go in a different direction from the Road Dahl tale. The original story ends with Mr Fox digging secret tunnels to farms for raiding while Boggis, Bunce and Bean sit at Mr Fox's hole, waiting for Mr Fox to show himself (waiting till the end of time). The film shows that Mr Fox, though smart, can get beaten and Boggis, Bunce and Bean aren't just going to sit on their arses and wait around. Mrs Fox wasn't just cautioning her husband on his recklessness, but was giving a warning to not expect a book-faithful adaptation.
In fact, the film uses an original draft ending that has the Foxes in a supermarket.
Kristofferson is a Kit fox (Vulpes macrotis), a cousin of the Red fox (Vulpus vulpus).
During the toast at the end, Ash is drinking grape juice while everyone else drinks apple juice, implying that he's come to accept being "different".
At the end of the film, all the animals have been forced out of their cozy, traditional, countryside homes to begin squatting in what resemble sparse, concrete, urban housing-projects and have to get all their food from urban supermarkets where everything to eat is all processed and artificial. Sounds like most poor, urban, minority neighborhoods.
Mr. Fox said that the tranquilizers were enough to sedate a gorilla. You're probably thinking, "But if it's that powerful, won't that KILL a beagle?" Well, considering that we don't see any of the beagles (except the rabid one) after that...
Which leads to Fridge Brilliance: why didn't it kill Boggis? Because Boggis is shown to weigh 340 pounds. The average gorilla weighs about 320 pounds, meaning the sleeping powder would only be able to tranquilize a man of his weight.
Coach Skip only appears during the Whack-Bat scene at school towards the start of the film, then unlike the other animals, never appears again throughout the entire movie, even after the farmers start their crusade against Mr. Fox and the other animals of the area. Maybe they got him.
