Revealing mistake: When Alison discovers Nancy and Tom are dead you see Tom's dead face change in each closeup. When she rushes out of the door in a panic Tom's eyes move as she opens the door and then moves again as the door closes. (01:03:40)
Continuity mistake: When Charlie and the Sheriff are driving and the Sheriff says go back to Ol' Blues, there's cars parked next to the side of the building. When they pull in, the cars are gone.
Continuity mistake: When Sheriff Stevens is arresting John, he has his hand on the back of John's shirt collar as he lifts him up. But in the next shot, his hand is grabbing John's hair.
Continuity mistake: When Dan and Allison are in bed and they finish kissing, you can see their bare chests and shoulders and the sheet is around their waist. In the next shot of them, the sheet is over Dan's shoulder and when he rolls over, the sheet is covering Allison's chest, before she pulls it up.
Character mistake: During the surgery, one of the surgeons says to give the patient 25 cc's of cyatril. Then one says make it 35 cc's. 35 cc's (or 35 mL) is a full large syringe. The other doctor uses what looks like a 3 mL syringe and it's only partly filled. It seems the surgeons wanted 0.35 cc's.