Continuity mistake: Near the beginning of the film, Alfred freaks out when he sees Cropsy come up to the cabin window. On the DVD, Cropsy's face is seen as just dark and disfigured. However at the end of the film at the abandoned mine, you see that Cropsy's face has dramatically changed from being just disfigured to having more of a melted appearance.
Revealing mistake: In the scene where the burned man attacks the prostitute (the first scene after he leaves the hospital) you can see him stab her with scissors, but when he takes them out we can see that they're missing tips for safety (they're too thick to have broken off inside her). (00:12:50)
Revealing mistake: In the raft scene where the garden shears end up hitting parts of the raft, there is one scene where the shears cut through one of the planks of wood. You can see that the plank gets cut too cleanly. No matter how sharp garden shears are or how fast they are being swung around, wood doesn't get cut this way. This plank has been pre-cut.