Deliberate mistake: The 'NNN' news program shows a picture of some animal crackers in Frank's stomach. The problem is, they are still all in one piece and are pretty big. I don't think Frank would swallow them whole.
Deliberate mistake: Spoilers! When Black Manta is defeated, he is knocked unconscious and tumbles down a rock face after his helmet explodes on his face into the waters by the shores of Sicily. These currents and waves at best would have carried him to the rocks or the beach, leaving him on land or near it. However in the after credit scene he's somehow found out in the middle of the ocean on a broken drift wood. He would not have been carried back out to sea like that.
Deliberate mistake: At one point they use a Red Ryder BB gun (Yes, just like in A Christmas Story) and the guy says "You pumped it more than twice, didn't you" to his female counterpart when they shoot the bird. Red Ryder BB guns cannot be cocked/pumped more than once, due to the simple nature of the toy gun that it is.
Deliberate mistake: During the ice storm, Hoke brings Miss Daisy coffee because he figured her stove was out. A few scenes before that they are frying chicken on a gas stove. Gas doesn't go out during power outages.
Deliberate mistake: During the sting attempt towards the beginning, Douglas confronts Snyder on the roof of the building. A helicopter rises up from nowhere without making any sound prior to that.
Deliberate mistake: When Sarah, et al are surrounded by the Goblins in Goblin City, the first cannon fires causing an explosion in front of some buildings, one of which has a hanging sign with scissors on it. Later, after the squatty Goblin says, "Hey! I just fired you!" another cannon fires causing an explosion, and the very same shot is shown, only the first one was flipped. (01:20:15 - 01:25:35)
Deliberate mistake: There is just too much movement and detail in the synthetic skin masks. Peyton lost a large portion of his face in the explosion, and cannot make much expression with his own face, but somehow he can make the masks move perfectly just like a real face.
Deliberate mistake: Practically all movies incorporate the name of the movie within the dialog. However, they must remember the English language and tense agreement. On at least two occasions, Fishburne says "Come on Dodge, lets FLED." If they were so interested in incorporating the name within the script, they should have named the movie FLEE.
Deliberate mistake: In the scene where Marie is trying on shoes, a pair of powder blue high top Converse sneakers can be seen next to her feet. It must have been done intentionally, but since there is no trace of modern apparel anywhere else in the film (the closest would be the mere mention of hot pink dress fabric but, as it's not shown, we don't know what exactly Marie calls "hot pink") these shoes (and the fabric) can't be considered part of a thematic element or artistic license. (00:55:35)
Deliberate mistake: When Alexander is travelling to the future for the first time, it shows a speedy acceleration of the events around him. However, the planes that are seen flying by are moving at normal speeds, or at least speeds way too slow since they should be moving too fast to even see, since skyscrapers are being built in a matter of seconds.
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: In the prom scene at the end, there is a shot of a couple dancing with his hand on her rear-end. A counselor comes over and hits the boy's hand to make him move it. He complies, they kiss, and he puts his hand back when the counselor leaves. The camera cuts away to a different shot, and then returns to an over-head wide shot of the crowd. Down in the lower left-hand corner you can see the exact scene with the couple and counselor being filmed.