Deliberate mistake: In the scene where the FBI agents are transporting Lester Cowans in a car and telling him all his friends have confessed, for about three seconds the scenery goes by backwards. For some reason, the shot is played in reverse.
Deliberate mistake: In chapter 15 "Bad Service" as Kim drives away and almost hits the kids which are supposed to represent the "Burkittsville 7", count them. There are three girls and four boys. Rustin Parr kidnapped 8 kids; 4 boys and 4 girls. Kyle Brody survived so the Burkittsville 7 should be 4 girls and 3 boys.
Deliberate mistake: After Emily talks to inspector Girotti she starts a record player. Then she walks over to the window, sees Werner in the garden, and decides to go down. Between shots she appears behind him, which is wrong, as the song from the record goes on, but it's most probably intended. (00:30:45)
Deliberate mistake: When they are playing strip monopoly, Alice purchases Baltic Avenue and then Bill rolls the dice and Alice exclaims that he's rolled an "8" - putting him on Baltic Avenue. However if you look carefully at the dice (before Brenda quickly scoops them up) you can see they show two 5's. (00:40:05)
Deliberate mistake: When Sidney is typing the message to the police, you can see that there are red lights flashing, which must mean the police are there, 5 seconds after she types. Obviously deliberately done for the humor. (00:29:30 - 00:30:25)
Deliberate mistake: The floating contact mine that explodes at the end of the movie would never have been put in an evidence room in a police station. Barring that error for the plot's sake, FCMs weigh 450lbs and would have required a hydraulic crane and a cart to move it, not just a couple of guys. They also did not contain clocks. (00:42:40)
Deliberate mistake: The scene where Arnie takes Denis for a high-speed ride was obviously shot in a studio. Arnie throws an empty beer can out of a car doing 80+mph, so the window was rolled down - but his hair isn't ruffled at all. Alternatively, he used concrete as hairspray.
Deliberate mistake: The opening camera scene, that's supposed to be shot from Michael's POV as a child, is too high as noted that he's almost face to face with his parents at the end of the scene and then is only mid-chest up to the father when he removes the mask. The POV is also too high as he walks across the dining room and as he approaches his sister upstairs.
Deliberate mistake: When the red jeep is driven into the tree, two of the occupants are thrown through the windscreen with such force that they land about 15 feet away from the vehicle, one of whom was sitting in the back. But John, who was in the front passenger seat with no seat belt on stays put. Then calmly gets out seemingly uninjured? (00:32:30)
Deliberate mistake: Right at the end of the film, the two Norwegians (Lars and Matias) are seen chasing after Lars' dog in a helicopter. Notice how their clothing and the interior of the helicopter are not the same as they looked in the original 1982 film by John Carpenter. It's supposed to be the same event.
Deliberate mistake: When Douglas' fingers are chopped off, they are hit from the right side by the blade, but they inexplicably fly directly forward (instead of to the left as they shoot), somersaulting smoothly through the air in a clean, uniform manner. Obviously done for the sake of the 3D effects in the film as they fly directly towards camera, but completely defying the laws of physics.
Deliberate mistake: One of Eva Marie Saint's lines in the dining car seduction scene was re-dubbed. She originally said, "I never make love on an empty stomach," but it was changed in post-production to "I never discuss love on an empty stomach." It is said that the censors felt the original version was too risqué.
Deliberate mistake: It's not particularly believable that the away team to stop the assassination would consist of the ship's entire senior staff, and raises the question of who was left in charge of the bridge (the answer: apparently nobody, as they return to a completely deserted bridge). Of course this is dramatic license, and at this point the audience won't care or likely even notice.
Deliberate mistake: When the Neski file exchange takes place in the beginning, the Russian says "You can see who stole the money" and the camera shows the Russian documents. The documents (written in Russian), are in fact, a "Journal of Military Activity of Russian Army in April 1945." It is completely bogus and have nothing to do with the film. (00:07:15)
Deliberate mistake: When it starts raining so that "things couldn't be worse" according to Seth Green, the younger fat hillbilly pulls out an umbrella. Why would he have one when he is trying to hunt someone down and kill them? This was obviously put in for comedic purposes but doesn't play well in the movie. (01:05:40)