Continuity mistake: In the beginning of the movie the school is named San Pedro High School, but later on it's San Paulo High School. (00:08:20 - 00:21:20)
Continuity mistake: In the scene where Eric Stoltz's character, Keith, fresh out of the shower, is confronted by his father about the college money, he has two distinct hairstyles. These two hairstyles show up again at Hardy's house party.
Continuity mistake: When Hardy is giving Keith a hard time at the gas station by dropping the money on the ground, Keith picks it up, then all of a sudden the shot zooms in and Keith is holding the engine dip stick.
Continuity mistake: In the scene at Hardy's house party, Keith pushes Hardy up against the wall at the bottom of the stairs, and two of Hardy's buddies immediately grab Keith and pull him off. But the guy on the left changes. In the shot where he first gets grabbed, that friend is a guy with a slight curly-haired mullet and a dark flannel button-down shirt. Seconds later the shot shows a guy with long bangs and a dark sweater... a completely different actor. It remains this actor for the rest of the scene.