Revealing mistake: During the scene in which Lou forces himself on Kim in the lunchroom, donning a black ski mask, Kim's brother Alex jumps up to his sister's defense. Just before Alex throws his first punch, Kim screams "Michael," referring to the actor's real name Michael Tough. Kim then correctly screams "Alex," the name of the character he was playing in the film.
Visible crew/equipment: Kelly gets spooked and heads to the door to check to see if anyone is around. She proceeds to open the front door and the scene quickly cuts to an exterior shot of her looking out the door, and right above the door is a black boom microphone.
Continuity mistake: Kim is at the kitchen table with her brother Alex. Kim has a necklace on. Kim asks Alex about having a date for the prom and all that is around her neck is a gold chain. The shot then cuts to Alex and then back to Kim and now there is a gold star hanging from her necklace.