Continuity: In the scene where one of the hall monitors is folding the principal's note into a paper airplane, watch his cigarette. It goes from being in his mouth, to being in his hand and back without him moving it.
Factual error: When Tom is talking to Riff on the phone, he mentions that he is listening to the Ramones's latest album. However, the song playing as he says this is "I Wanna Be Your Boyfriend," which is from the Ramones's first album
Other: Before the hall monitor folds the note into a paper airplane, the note has creases as is it was already folded into a paper airplane, and then flattened out for a different take.