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.
When main character leaves her friend in the car at the graveyard, light was left on in the car, but in the next shot of the friend, there is no light in the char shown.
When girl is killed with an iron, light in the scene changes between 2 shots.
Lynn completely misses the killer when he reveals himself to her, but it's shown like she hit him in the next shot.
Chris get's punched, but the hit never contacts, yet it's shown like he got hit.
When killer cuts of the head of a dancer on the stage, you can see the obvious part of the doll.
At the end of Lynn's run through the woods, there is an obvious light reflection the camera on the left side of the screen.
Phone can be heard ringing while not hang up.
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.
At the end of the movie, killer can be heard screaming after being hit by a guitar, but is not shown doing so until few shots after.