Revealing mistake: Right before Dodger walks into Georgette's room in search of Oliver, she talks to herself in the mirror. But at one point the reflection moves when she doesn't. (00:43:10)
Revealing mistake: Toward the end film when the female counselor finds Uncle John dead and a camper hanging, the hanging camper's eyes are shaking as he's trying to keep them open in a certain way.
Revealing mistake: When Harry and Samantha are shot at in the elevator you can see a number of the dark marbles that were used for the effect rolling on the floor.
Revealing mistake: Near the end, when Eliot enters Frank's office with his rifle, he accidentally shoots into the ceiling. He shoots it at a slight angle, but the rubble falls right on top of his head instead.
Revealing mistake: When Dr. King checks on Mrs. Boynton, the dead woman opens her eyes by her own volition before her head rolls back. (00:45:00)
Revealing mistake: In the scene where Zuckerman is thrown to the floor in the gym and handcuffed, you can hear the handcuff ratchet click as it's placed and closed on her wrist. As the other agent moves away, you can see that the handcuff is open and not actually closed around her wrist. (00:31:00 - 00:31:50)
Revealing mistake: When one character's killed, stomach sliced open, you can see the wire yanking open the prop stomach to the left of the camera.