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: There is a huge security breach in the scene with Robin Williams and Christopher Walkin walking at night. The Security SUV limousine is more than 30 metres away from them. It should be pacing them in case of an emergency and be right next to them on the sidewalk. It appears the reason it is so far back is because at the camera angle the scene is shot at, it makes for a good background element which you would not see if the Secret Service followed protocol.
Deliberate mistake: After takeoff, an exterior shot of the plane switches from a Boeing 757 to an Airbus A320.
Deliberate mistake: After Doug finds where Minuti was killed and set on fire, he walks over to a dock where he sees Minuti's arm being eaten by alligators. Minuti had been dumped in the water 4 days prior, yet his hand is perfectly intact with no signs of burning, bite marks or weather/water damage of any kind.
Deliberate mistake: The first time the warriors ride out during the full moon, the shot of the moon shows that it is in the phase of "half moon".
Deliberate mistake: During the scene on the train in lounge car, a picture on the wall prominently shows an ALCO PA locomotive. The movie was set in 1945, but this locomotive was first produced in 1947.
Deliberate mistake: When Harrison Ford and Mary Lynn Rajskub are crossing the tracks, its Rajskub who's driving the car, not Ford. This is because the filmmakers originally had Rajskub driving the entire way. They later refilmed the drive with Ford driving, but kept the shot of them crossing the tracks the same. Ford and director Richard Loncraine confirm this on the special features of the DVD.
Deliberate mistake: At or near the beginning there is a scene with autumn leaves. The colours and amount are just not consistent with the date of September 11. They seem to be about 3 or 4 weeks ahead of schedule.
Deliberate mistake: When the rocket (a replica of an Atlas booster) launches, it makes it all the way to orbit in one piece. In reality the Atlas was a two-stage rocket, and the first stage would've been jettisoned long before reaching orbital velocity. (Undoubtedly the filmmakers decided to fudge this, to avoid dealing with the issue that the rocket didn't launch over the ocean, and the first stage would've fallen onto some innocent bystander's property.).
Deliberate mistake: When the armored car hit's the police car the police car flies up in an explosion. Due to the size, style, and weight of the armored car, the police car should've been run over and crushed. (01:02:05)
Deliberate mistake: At the very end when they are all running to get the car started, the boy is the last to hop in. In the first scene, he is well along side the car, but in the very next shot he is farther again. In the last shot, he is closer to the door and finally gets in.
Deliberate mistake: In all the shoot-outs, the bullets that hit the cars spark, which bullets do not do, and leave no hole, dent, or even a small scratch. They do, however, break the glass.
Suggested correction: This isn't correct. In the big shootout towards the end, gunshots leave holes in car doors and break car windows from both sides of the fight.
Deliberate mistake: When the police blitzes the "traditional English breakfast" joint, in the background the menu display advertises "Omlettes", and in the close-up on the owner you can read the word "Mashrooms." It's surely deliberate to show how the joint is not exactly ran by purebreed English people - although it should be noticed that there is an inconsistency with previous scenes when the board was different, and even the word "Mushrooms", handwritten, was spelt correctly. (01:23:00)
Deliberate mistake: When Jenny writes "dick" on Matt's forehead, she does not stop the beam but the word is written with the letters separated.