Continuity mistake: When Shelly throws his wallet to Vera, he has a silver band around his left arm. Then when he says "Excuse me, but I believe that's my wallet", it has disappeared. (00:29:50)
Continuity mistake: When the crew is outside and they're going to lock Blair in the tool shed, you can see someone nailing wood across the window on the front of the shed. The pieces of wood are horizontal. In the next shot (inside the shed), if you look at the window in the background, the strips of wood are vertical. When Mac goes back outside, the wood is horizontal again.
Character mistake: The news article on the murdered gentleman David Carradine discusses has the word existence spelled wrongly. It says existance. (00:37:57)
Continuity mistake: When the scientist's face starts to melt, the stuff on the wall keeps changing all the time.