Continuity mistake: In the scene where Mike Teavee has smashed up the red pumpkin-looking thing, he smashes it cleanly into two or three quite big pieces. When his father says "Mike, please" the pieces behind him are much smaller and all over. (00:41:35)
Continuity mistake: During Mike Teavee's scene, his father has some bits of hair overlapping the arms of his glasses. On the right side the bits appear and disappear from shot to shot.
Continuity mistake: At the nut factory, when Mr. Salt is there with the ladies, and he is walking up to the podium, the microphone is facing towards where he is walking from. Then in the next shot when he is at the podium facing the ladies, the mic changes direction and is centered, facing him.
Continuity mistake: When Veruca is choosing a squirrel, she heads for the last one in line, furthest from the ladder. Then after it cuts away and back, she is headed towards the middle of the line, but then she is headed for the last one again. When the squirrels jump her, she is about 1/4 of the way down the line, starting from the ladder.
Continuity mistake: The jacket that Violet wears has a zip. However, this zip disappears without trace once she is a blueberry, and remains missing for the rest of her existance as a blueberry. Violet's body was done in CG animation, so it could not be that Violet had to change into a different costume. There was no reason why the zip couldn't remain, it just seems like the CG makers got tired of it being there.
Continuity mistake: When in the Chocolate Room, Mike Teavee crushes the pumpkin into three pieces. It then zooms out and shows him crushing it into three pieces again when Mr. Teavee comes up.
Continuity mistake: When the factory gates open for the contest winners, the shadows in the courtyard change between shots. [This is a reference to the first film in which the shadows shift a lot. It is also shown in other parodies of the original film, eg, the Family guy episode "Wasted talent". Still a valid mistake.]
Continuity mistake: Just after Violet Beauregarde has been rolled away by the Oompa Loompas, Willy Wonka appears next to Mrs. Beauregarde and tells her how they've tried it on several Oompa Loompas, they all ended up as blueberries and that it's "really weird." When he finishes speaking he is smiling, and the camera immediately cuts to a shot of Wonka and Mrs. Beauregard from another angle, and he's not smiling anymore, with no time to change between shots.
Continuity mistake: The tire track of the rightmost truck (in the top-down shot) is completely wrong. All 5 of the trucks were parked parallel. Besides, we can see only one pair of tire tracks per truck, but when a truck turns, the path the front wheels move on has a larger radius than the one the back ones move on thus creating two tracks. All this was OK just a shot before. (00:04:00)
Continuity mistake: In the scene where Violet and her mother are talking about the trophies, the trophies in the trophy cabinet behind them changes between the first shot and the second shot. (00:21:50)