Other mistake: While working in the basement, the young Hugh Crain gets his right hand sliced badly by a fan. When the story next jumps forward to the present time, the first thing we see is Hugh grabbing a handful of dirt with the same hand and there is barely a scar on it.
Continuity mistake: When the sheriff is telling Hugh he can leave whenever he wants, in the shot of him saying he wants to make sure Hugh will walk out of the station without suspicion, he has his right hand placed on the desk, with his arm mostly straight. When the shot cuts to a closer angle, his arm is bent at the elbow. (00:02:30)
