Continuity mistake: When Sidney is talking to the killer in the police station, her phone has a "Nokia" sticker on the bottom of it. Later in the scene, it's gone. (01:29:15)
Continuity mistake: Gale and the killer go flying through the basement door, you see the door opens out, but when they crash through it, it opens in. Its not a two way swinging door, because you see the hinge at the top of the door to open it out, not in.
Continuity mistake: When the bodyguard finds Gale eavesdropping on Dewey and Jennifer, they soon confront each other and Tom is sitting in a chair with his left hand on the arm rest. In the next shot Tom is smoking a half finished cigarette with his left hand, but he had no time to change the hand with the cigarette in it between shots. (00:40:00)
Continuity mistake: In the beginning when the killer is trying to kill Cotton, he pulls a book case on the killer, but if you look carefully you see that the killer slides to the side, despite the fact that the book case is meant to have hit him. (00:08:55)
Continuity mistake: The knife that was thrown at Dewey left the killers hand with blood all over the blade, but was perfectly clean when the butt of it hit his head to knock him out at the top of the stairs. (01:26:55)
Continuity mistake: The second time Gale shows up at Jennifer's driveway (right before the place blows up), one can clearly hear her turn off the lights and remove the keys from her car. Yet, when she opens the door, the car still makes that beeping noise that happens when you leave your headlights on or leave your ignition key in the ignition. (00:37:10)
Continuity mistake: When Sarah tries to fix Roman's statue's head, her hair is over her face, when she goes to answer the phone her hair is pulled back behind her ear. (00:23:20)
Continuity mistake: Gale's bangs change lengths throughout the film.
Revealing mistake: Stunt double is visible when Dewey falls down the steps at Milton's house. (01:27:00)
Continuity mistake: In the scene where Jennifer gets killed and falls through the mirror look at Dewey's hair it's all messed up, but in the scene right after that when Dewey and Gale are looking for Tyson his hair's all combed back again.
Continuity mistake: At the part where Sidney is on the set of her house and the killer is chasing her up the stairs, she runs right by the plants, but in the next take she is right next to the plants just about to throw one. (01:05:25)
Continuity mistake: Dewey rolls down a hill after shooting at the killer. The cut on his forehead changes shape from circular to two parallel lines then to a straight line and a waved one.
Continuity mistake: In the scene where Dewey and Gale are having lunch, Dewey asks her "Why would the police come to you?" In the background, a waitress in white walks by. Then they switch to Gale and the waitress has vanished. (00:28:30)