The blood on Jenny's nightgown changes when she enters the room with the circle on the floor.
When Jenny first enters the spa, her hands are both on the door frame. When it cuts to an interior shot, only her right hand is on the door's knob.
As Jenny exits, the hunter pulls out his pipe and is holding it in his hands. Cut to close-up, the pipe's hanging from his mouth and he's holding matches.
The main axeman's hair and beard change length throughout the film.
John only unhooks the first two buttons of his shirt. Suddenly all of the buttons are unfastened.
When the audience hears Jenny saying, "Hey, you're not so dumb after all," her mouth says, "Maybe you're not crazy."
The shadow of the cameraman crosses over Jenny as she enters Mrs. Abercrombi's empty cottage.