Revealing mistake: When Henry's mom is pushed off the cliff her cable is visible.
Revealing mistake: When Jason (in Robert's body) is shot in the head at the end of the hall, a close up reveals the bullet hole to be obviously just makeup. (01:05:35)
Revealing mistake: While in the convenience store, watch the arcade screen the punks are playing, they are getting very excited about the game, however anyone who has played Street Fighter 2 will notice that they are merely looking at the demo version and even the words "insert coins" are displayed on the screen.
Revealing mistake: The 'bear trap' clearly has no spikes in it, so how could it have wounded Nathan. This is ever so clear when Tori prises the bear trap open to get his leg out, and it snaps back. (00:52:00)
Revealing mistake: At the end of the movie with Matt Cordell (Maniac Cop) chasing after the detective in a police car while being set on fire, you can see the safety goggles under his mask in several of the changing shots in this stunt scene.
Revealing mistake: Right before the witches burst through the roof of Max's house, after they retrieve the book, you can see the charge used to set off the explosion in the window just below where they exit.
Revealing mistake: When Alferd runs from the saloon with a lynch mob behind him, we can see a line in the dirt ahead of him that serves as a marker for where he is supposed to run.
Revealing mistake: Dr. Piper gets her left ring finger cut off by a Totem, yet while she is running, the finger has reappeared. (00:09:00)
Revealing mistake: When they first arrive at camp and Joel goes to use his inhalers, the mouthpiece is actually in the storage position rather than the actuation position. The puff sound must have been added in later because the inhaler cannot be activated when it is put together that way. (00:22:20)