Continuity mistake: While Father Malone is drinking his wine you can still see the cork laying on the table. He finally gets up to try to catch Bennett before he leaves and the cork has mysteriously put itself back into the bottle. (00:05:00 - 00:05:45)
Visible crew/equipment: After they've killed the snake, Alice says "Is it dead?" and as the camera pans up, the boom mic's shadow is visible moving across the wall, directly over Ned's head and the red box. (00:26:05)
Continuity mistake: The roof of the Chessman House changes, going from having a middle roof to no roof in the middle.
Suggested correction: You can't see the full roof in the second image because it's a low-angle shot looking up. But if you look closely, you can indeed see a little bit peeking out, and even see the tips of the two attic windows. Furthermore, it was a house exterior they built specifically for the film... what purpose would there be for removing the roof for this one random shot?