Factual error: Ashley Judd is convicted of murdering her husband for the insurance money and that would make it a first degree murder charge (first degree meaning she planned the murder). Because of that there is no way she would have been eligible for parole after just 6 or 7 years.
Other mistake: During the scene where the Japanese are being rounded up and taken to the internment camp, the camera is panning over the crowds of people walking down the street. Half way through this scene, there is a woman and a little girl, who seems to be carrying a stuffed Elmo, hardly appropriate for the time period.
Visible crew/equipment: In a scene not too long after Tom Cruise attempts to revive a hooker who has OD'd, he is speaking with an older gentleman. The three are in a bathroom and the hooker is passed out on a chair. One of the shower or light fixtures toward the left of the screen is shiny, and in a shot during which the camera briefly tracks in reverse, you can see the camera, cameraman and the focus puller reflected. It's pretty clear and not all that fast.
Continuity mistake: The bottle of Peach Schnapps that Trip (Josh Hartnett) brings to the dance is alternately full and half empty during the scene. When Trip pulls it out, it is new and unopened. He hands it to Lux to drink, at which time it is nearly empty. He then drinks from it, and it is about half-full. He next hands it to the other couple, at which time the bottle is nearly full again. (00:57:56)
Factual error: The priest says that St. John saw the number 666 in his vision, but it was actually 999 inverted. I'm not sure, but I don't believe St. John read modern Arabic numerals like we do. Didn't he read Roman numerals? I think if St. John saw the number 666, it would actually be DCLXVI. (01:05:40)
Continuity mistake: When Silent Bob renders the demon disabled by using the anti-odour spray, you see him take the spray out of his coat and spray with his thumb. However, it cuts to a front view, and he is clearly seen using his index finger. It then cuts to Bob's rear, and he is, again, spraying with his thumb.
Continuity mistake: When Nicholas Cage is being escorted to fetch the roll of film from his car, there are a few scenes where the accountant is holding a gun to Nicholas's head. When the camera is directed at the accountant, two hands can be seen grasping the gun, but when the camera is facing Mr Cage, initially there are two hands but after the next switchback there only appears to be the one! (01:20:50)
Continuity mistake: In the flashback to the death of the headless horseman, when the horseman's steed gets shot and falls to the ground, the blood and the wound are on the right side of the horse...later in the scene when the horse is seen again, the wound is on the left side of the horse. (00:16:45)
Factual error: Early in the movie when the interior of the downed aircraft is shown (underwater in Chesapeake Bay), with the eerie picture of Dutch's wife and the congresswoman's husband sitting underwater in first class with their hair waving slowly in the current, they are shown on the right side of the aircraft (the left side as we are looking at them, but the right side of the plane proper). Yet, when the airline representative is discussing this "problem" (non-married-to-each-other people apparently flying as a couple), they are announced as sitting in row X (don't remember), seats A and B. Aircraft seating is always done from left to right - i.e., the A and B seats would be on the other, or left, side of the aircraft.
Continuity mistake: At the end of the movie when Michael chases the delivery truck in a red Ford Contour, he crashes into a bus and the car spins several times. If you watch closely you can see that after the crash the left headlight is very badly damaged and the right one is missing, but the next scene shows the car almost undamaged.
Audio problem: After the part where Johnny Depp finds his bookstore friend dead, he gets back in the cab. After driving for a while, he tells the cab driver to pull over to the phone booth. The cab driver says "No problem, sir" but you can see the cab driver's lips in the rear view mirror, and they never move.
Other mistake: Right at the very end, when all the prisoners are standing in the room, it starts to slowly zoom in on Alice in the middle, but watch the blonde girl on the left of Alice - she starts laughing for no reason at all as Alice smiles to herself. I don't think it had anything to do with the film either, because it didn't show any reason why she would just start laughing like that.