When the skull is biting Eric's neck during the movie's climax, his sweater vest is clearly seen in wide shots, but he is not wearing it in the close-up.
Length of the candle in the bedroom.
Real human skulls are not connected to the jaw bones.
As Eric watches the skull fall down the stairs, a stick is visible trying to tip the skull over.
When the birds are apparently scared by the skull, a rock is visible being thrown up to scare them.
When the ghost of Marianne is knocked over because of the chair Eric threw at her, her arms fly off.
When Eric is slapping Mickey at 55 minutes the slapping sounds are heard after the apparent impact.
The shadow of a boom mic is visible when Jenni is talking to Reverend Snow about her mother's death.
Boom mic can be seen when Mickey is spying on Eric and Jenni at the beginning of the film.