Deliberate mistake: Leaven spends too much time thinking about if 645 and 372 are prime numbers to be believable. But she knows the factors of 649 and the result of 26 to the power of 3 almost immediately. Plus anyone with any maths knowledge whatsoever would know that any even number (or one divisible by 5) can't be prime, so 645 and 372 could be dismissed without even thinking about it.
Deliberate mistake: During the mob scene outside Saito's love nest, the same black Saab is seen getting firebombed twice. It was shot from two different angles, with the two shots played about a minute apart to give the impression of two cars getting bombed. Also, in the first angle it is clear the car has no engine.
Deliberate mistake: In the scene in which Ace is in the asylum, he breaks into a storage closet to view Finkle's belongings that were left behind when he escaped. At first the doorframe is such that the door closes against about an inch of wood, meaning the lock would be behind this wood, so Ace couldn't pry it open. In the closeup, the door's flush against the frame so Ace can use the sign to get between the door and the frame. In the wide shot it's back to how it was. (00:58:55)
Deliberate mistake: There are a number of things wrong with the roller coaster scene (besides the obvious impossibility of a crash like this actually occurring):1) The restraints use ratchets to lock, not hydraulics. A coaster of this type wouldn't even have any hydraulic lines.2) No roller coaster has restraints that lower by themselves.3) The attendants didn't check all the restraints. This is ALWAYS necessary, on ANY ride.4) On any roller coaster, the Dispatch button (or "Start" in the movie) must be held down until the train is clear of the station. This is a safety feature to make sure the attendants are clear of the moving train. If the button is released before the train is clear of the station, it will stop.5) At the bottom of the lift, the lift chain curves to follow the track into the station. This is impossible, a lift chain cannot curve horizontally, only vertically (normally at the top of the hill).
Deliberate mistake: When bars are placed on Harry's windows, so he does not escape, it is apparent that his windows have complete leaded panes of glass. Yet when Harry is being rescued, Ron and Harry speak with each other, even in low voices, through his visibly closed windows. (00:08:00 - 00:09:00)
Deliberate mistake: In the shot near the end of the film where Donnie grabs the keys for the station wagon, you can see a Blockbuster Video member card in a cup. That card design wasn't used until the mid to late 1990's. This movie is set in 1988. Deliberate as it's a product placement, but still wrong. (01:37:10)
Deliberate mistake: Every time Nicholas enters his gate at home, it's daylight and then when he drives up to the house it is night. Either he has a 300 mile property or there is something else going on. It would appear that it is deliberate as it happens many times in the film. Symbolically, Nick is leaving the world as he appears with wealth and privilege (light) and entering the real van Orton world of solitude and sadness (dark). (00:09:00 - 00:09:55)
Deliberate mistake: There is one scene in the movie where Heath Ledger reads a Latin sentence in a book. As he is translating the sentence, he goes over the words one by one with his finger. This would never be possible in a Latin sentence, because words in Latin are never in exactly the same order as in English. Words that actually belong together can be placed at opposite ends of a sentence.
Deliberate mistake: Has there ever been a more obvious body double than the one used for Angie Dickinson in the shower scene? Not only does the top of every shot stop right at the collarbones, she is much taller than Dickinson, she has a much deeper tan and (of course) her breasts are much, much bigger.
Deliberate mistake: In Raymond's flashback to "when he was once loved" there is a scene where he is having dinner with the Senator and his daughter. Evidently someone didn't feel that this scene was quite long enough as shot. Raymond picks up a piece of meat on his fork, puts it in his mouth and then begins to laugh. Then he puts the empty fork back into his mouth, removes the piece of meat and replaces it onto his plate. Obviously, the film was reversed briefly to give the illusion of a longer scene.