Continuity mistake: At the end of the fight in the gym, Mr. Horn comes in and stops it. Yet in the previous overhead shot, he is nowhere to be seen. The shots are meant to be directly connected - watch Cellini's hand. In the overhead shot, he starts brushing his hair back. In the close shot, he finishes the motion from the exact point he stopped in the overhead shot.
Continuity mistake: When Barry gets taunted by the coach when he's up on the rope climbing, especially the part when the coach says "keep going lady, don't even think about quitting," in the shot when the camera pans on Barry he is just 10 feet up on the rope, but when the camera pans down at the coach and the rest of the class it looks like he's at least 20 feet up on the rope.