Continuity mistake: When Dean, his brother Eric and Bailey are taken back to the house. Dean and Eric are taken away and tied up. As Sheriff Hoyt is threatening them we see Eric's face has blood on it. As the scene keeps going, the blood on Eric's face keeps disappearing and reappearing each time we see him.
Continuity mistake: The blood on Bailey's face disappears and reappears while Luda Mae is washing it.
Factual error: In the scene where Eric and Chrissie are by the pool, the song "All Right Now" by Free begins to play in the background. The movie is set in July 1969, and this song wasn't released until mid-1970.
Revealing mistake: After the accident, you see the car's gear is in park on the steering column.