Revealing mistake: When the killer is dragging the girl's body with the meat hook, you can easily see that it is a doll. (01:18:45)
Revealing mistake: When Julie is in the room filled with ice, some of it jiggles when she moves it, probably a prop made of jelly. (01:31:20)
Revealing mistake: When the car crashes through the billboard/back of the beer stall, you can see in the overhead view that the stunt double took the fall wearing under the light yellow shirt a thick white undershirt with padding. The camera then cuts to the hot-looking Mr. Ryan Phillippe who, being much less unconcerned about impact and splinters, wears nothing under his shirt. (00:41:35)
Revealing mistake: In the sequence of the accident, skid marks from previous takes are visible on the asphalt right before the car does the little swerve to avoid the obstacle on the road. (00:14:20)
Revealing mistake: When Barry is chased by his own car, skidmarks from previous takes can be seen on the asphalt. Not many cars would take a sharp turn to point at a billboard. (00:41:10)
