Near the beginning Jesse goes into the principal's office. Before he goes in he has a "five o'clock" beard shadow, but when he is in the office he doesn't have the beard.
When Jesse and Nova are talking after adjusting the speed of the disco ball, Jesse says, "I'm a bad guy who is going no where and that's the only reason." Jesse actually says, "I'm a bad guy who is going no where and that's the only reason I'm here." The words "I'm here" have been dubbed out.