We see a girl cry in pain while her hand is being hacked with an ax, but she was already killed before that.
When Lynn talks with her boyfriend about digging up Billy, the light of the scene changes between 2 shots.
Lynn leaves her companion in the car at the graveyard, with the light turned on, but there is no light in the following image.
When a girl is killed with an iron, the lighting in the scene changes between two shots.
Lynn completely misses the killer when he shows himself to her, but it appears that she hits him in the next scene.
Chris gets punched, but the hit never makes contact, despite the fact that he appears to have been hit.
When John cuts off the dancer's head on stage, you can see the obvious stump of the dummy used.
After Lynn's run through the woods, light reflects off the camera on the left side of the screen.
Despite the fact that the phone is off the hook, it still rings.
At the 12:49 mark, there is a quick shot of Lynn's arm's reaching for "Billy" when she confronts him about Mary's death.
John can be heard screaming after being hit and electrocuted by a guitar, but the visuals don't match up until a couple shots after.