Other mistake: When Scott is delivering the hardware store supplies for the play, the cans of paint he is carrying awkwardly flip about like empty ones, and when he drops it makes a hollow sound. I'm sure they are meant to be full.
Continuity mistake: When Scott turns into the wolf for the first time in his bathroom, the position of his blue coat on the toilet seat keeps changing.
Continuity mistake: At the very end, Pamela tells her boyfriend to drop dead and walks away, off to her right. But in the last shot where Scott is hugging his girlfriend and his dad, if you look just to the lower left of them, not only is Pamela still just standing there, but she's to the left of where she was standing before.
Visible crew/equipment: When the wolf is "surfing" on top of his van, he does a hand stand, and you can see the handles he's holding onto for balance. They aren't there when they are surfing standing up.
Continuity mistake: When Scott enters the dance as the Wolf, and he's walking through the crowd, you can see Chubs is right behind Mick and Pamela, and Stiles is next to Chubs. When the shot changes, Stiles is now behind Mick and Chubs isn't seen. Scott walks past Mick and Stiles and in the next shot, he hasn't passed them yet and Chubs is back behind Mick.
Revealing mistake: After the first game in the locker room, Scott notices a 6 inch long hair on his chest, the hair is visibly taped to his chest with scotch tape.