Other mistake: When Laurie has her episode in the bathroom about killing Annie, the clock stays at 7:03 the whole time.
Continuity mistake: In the opening scene at the beginning of the movie, the Sheriff and Fish & Game diver are going to tag beavers. There is a clear shot of the diver under water at the beaver dam with a white oxygen tank. Shortly after he is attacked, part of his suit surfaces in the water with a black/gray oxygen tank, not white.
Revealing mistake: When the man pushes Leroy's body down the basement stairs, as his body is sliding down, when it's almost to the bottom, you can plainly see Leroy lift his head up as he's sliding, although he's dead.
Plot hole: In the end of the film it is heard the police want to exhume the body of Charles Lee Ray from his grave site in New Jersey. Now when Chucky and the crew get to the grave site they find and kill a coroner who is digging up the body. He is the only one there at 1am, by himself, a lonely coroner without any police officers, after all this is a police investigation and I doubt the cops would have him there alone. Then right at the end the Detective who is hunting them arrives. Now he is a cop from Lockport, about six states away. A. Why did he drive all that way to see the body? B. A cop from all the way down there shows up but no new Jersey cops are at the scene?
Visible crew/equipment: Near the beginning of the movie, the old priest is in Northern Iraq and you can see the shadow of a microphone on his hat.
Continuity mistake: At the start of the film, the dog is seen going from room to room looking for food. Just before he goes into Dana's room, someone can be seen through the crack in the door, moving from left to right.
Revealing mistake: In the opening scene where the zombie kills Johnny. When they fall against the tombstone you can tell it is a dummy.
Continuity mistake: When the old car blows up both of the dead zombies are gone. (00:21:40)
Factual error: When they're first entering the whaling camp, a penguin startles Miller. That penguin was a black-footed penguin, which is a bird native to much warmer climates. If that little guy had actually been in Antarctica, he would have died within minutes. (00:20:40)
Factual error: When Janet Leigh is shown lying dead on the floor of the shower, there is a close-up of her open eye. The pupil is contracted to a pinpoint (obviously due to the bright lighting) where it should have been dilated. After the film was released, Hitchcock heard from several ophthalmologists who pointed this out and suggested he use belladonna eye drops in the eyes of "dead" people in future films, as the chemical prevents the pupils from contracting. (00:48:30)