Gaffes

When Sally is showering herself, the amount of shampoo in her hair changes from shot to shot.

When Alfred is pinned to the wall, Cropsy has his hand around Alfred's throat. Later, when Cropsy is waving the flame at Todd, there is a shot with Cropsy's hand still around Alfred's throat.

During the end scene in the barn. The Cart comes down the rail track, nearly hitting Todd, and smashes into another cart at the bottom of the track. A few seconds later you can clearly see the cart is back at the top of the track again.

During the raft massacre, the hedge clippers are shown to be bloody or clean between shots.

The blood bag in Fish's shirt bursts before Cropsy's shears ever come into frame. Additionally, if you look closely you can see the string that pulls on his shirt to release the blood.

When Cropsy is set on fire at the beginning of the film, it is possible to see his crash helmet.

When Cropsy stabs the hooker with the scissors, a close-up shot shows the scissors are cut off to fit her stomach.

The scene where Glazer picks up firewood as he heads back to build a fire for Sally, he's obviously wearing a wig. This was because this scene was filmed later and they were trying to match his hair to earlier scenes.

When Glazer picks up the fold-over packet of matches from the camp, he shakes them as though checking a box of matches. The audience even hears a box of matches shaking, even though cardboard, fold-over-style matches do not rattle.

Sally only removed her T-shirt and left her panties on when she got into the shower.

When the kids on the raft are paddling towards the canoe, you can hear the kids being very vocal, making lots of noise, but none of their lips are moving.

When the helicopter arrives with the police at the end of the movie you can see someone holding a movie camera in the passenger seat.

At the very end of the scene where the campers are briefed for the canoe trip, Karen jolts and hits something on the table. Having no relevance to the story, it looks as if she was startled by a real insect on the table and they didn't bother editing it out.