Continuity mistake: Chuck and Ferdie are among six people who a driver drops off at an abandoned lodge. In the long shots of the lodge, rain is falling at a very sharp angle but in the close-ups the rain is coming straight down.
Audio problem: After Moose Matson is shot in the cop and car chase, Moose Matson, says, "Pull over, will ya?," but his mouth isn't moving.
Continuity mistake: Ferdie squirts oil on the face of Chuck. Chuck wipes his hand across his face and slaps Ferdie, leaving oil on his cheek. In a close-up, Ferdie cleans his face with a handkerchief but when he pulls the handkerchief away, there is no oil on it. The oil had obviously been cleaned off his cheek before the scene was filmed.
Visible crew/equipment: After the moving candle/ghost incident involving Ferdie and Camille, and before Moose Matson's money is discovered, Chuck and the doctor come running in, and they all start yelling and talking, there is a person (probably a crew member) briefly visible in the round window in the door in the background.