Deliberate mistake: Within the final crash scene, in the shot where the flames are first shown exploding through the cabin, you can plainly see that all the seats (especially the aisle seats) are empty. In addition, this shot takes place after several shots depicting cabin breakage, and debris flying everywhere. Here, nothing is flying anywhere, and nothing is broken.
Deliberate mistake: At the end of the film when Pacino and the gangsters are shooting each other on the escalator, the escalator takes a long time to get to the bottom, way too long.
Deliberate mistake: In the sequence where Jack finds his friend, and then the cards he is holding counts down to the explosion. Jack runs out, and the house explodes throwing the cop car into the air. If you look close, you can see the piston that launches the cop car and then falls back down. (00:24:40)
Deliberate mistake: In the scene where Sam is swinging from the hospital window, you see him first from the inside. Now he is obviously being pushed (from a crew member) so it looks like he's moving back and forth smoothly. However, when seen from the outside he couldn't be pushed and so when swinging by himself, he was actually bouncing off the walls. Inside this would have been seen. Also, inside it seems that the sky is clear, though outside there is a tree by the window.
Deliberate mistake: When the raptor breaks into the control room and is hopping around the computer workstations, we see sharp, distinct genetic coding projected from a computer screen and across the raptor's face (starting 1:55:50). Aside from the fact that computer displays have never projected focused images onto nearby surfaces, the projected text shown in this scene oddly reads from left-to-right, when it should actually be a flipped mirror-image (right-to-left). Spielberg probably realised this factual incongruity while filming but chose to use the left-to-right text for the sake of audience recognition, given that the multiple lines of "GATC" genetic code were already confusing enough. (01:55:50)
Deliberate mistake: When the saloon patrons pour through the swinging doors in pursuit of Packer, the same people are seen repeatedly. A relatively small number of extras are running around to the rear of the set and re-entering through the back so that they will appear to be a larger crowd of people.
Deliberate mistake: The movie shows events between 1939 and 1945 but the children look the same at the beginning and the end, they don't grow up. Pay attention to Danka Dresner, Adam Levy and Olek Rosner.
Deliberate mistake: Towards the end of the film, Josh is playing a game in the park with Vinnie, and Vinnie asks "What's that?", to which Josh replies "Schliemann Attack." However, this dialogue occurs while the game is still in standard opening theory and before Josh has played the move that introduces the Schliemann Attack (pawn to f5).
Deliberate mistake: At the end of the film its revealed all the murders were a hoax and everyone was in on the plan to set up Rex (Lee Majors). Why then exactly were Rachel (Vanessa Angel) and Patrice (Adrian Paul) talking together and pretending like they were trying to find the killer. In one of the scenes Rachel believes she has caught a photo of one of the men who she thought might be a killer and is showing Patrice, but Rex wasn't anywhere around. Therefore why were they pretending to find a killer or keep up the illusion whilst Rex wasn't around?
Deliberate mistake: The dummies are obvious when the jail bus is flipping over onto the railroad tracks.
Deliberate mistake: In the scene where Mary (Kate Maberly) emerges from the bath tub she glances uneasily at the camera for a brief second. (00:56:00)
Deliberate mistake: When Wyatt comes out of the Orientalist and joins his brothers in the street to tell them he's acquired a quarter interest in a game, a herd of cattle is passing them in the street but there's no dust kicked up by the cattle, when in reality there would be a lot of dust on a dry desert street in Arizona.
Deliberate mistake: It's meant to be a joke, but the way the famous punch scene happens is completely ludicrous. Darian appears to be flying in the air toward Nick to attack him, but there is no explanation of how she is doing this, and the way she was thrown back high in the air a few feet is something a punch can never do unless with inhuman strength. There's not any reason whatsoever that both of these things happen, except to give the viewers a laugh. A gun in this case would have made a whole lot more sense.