Continuity mistake: Mike has a shotgun as he is trapped in the hearse. He then blows the window to pieces and jumps out, and the shotgun is not in his hands. Then when he hits the ground, the shotgun is back.
Continuity mistake: At the beginning of the movie, when the girl is having sex with a guy, her legs are parallel to his, then it cuts to her sitting up on him. It's not physically possible for legs be flat on the ground whilst sitting up like that.
Continuity mistake: When Mike returns home, after the dwarves attacked him and the girls, he sits down with Jody. On the table next to them is a bottle of beer. But when Jody picks up Mike to take him upstairs, the beer has gone.
Continuity mistake: As Mike opens the box, just before the big fly jumps out, the box is sitting on a small mat on the table. But in the close-up of the fly popping out of the box, the small mat isn't under the box.