Revealing mistake: Dave is racing with the Italians, and the Italian puts his pump in Dave's spokes. In the middle of the bike falling over, you see a horizontal beige object with duct tape on it for a couple of frames, where you should see Dave.
Revealing mistake: In the fight against Apollo, Rocky's last punch of the second round conspicuously misses by a mile, but Apollo nonetheless acts like he has been punched, and there is a punch sound effect as well.
Revealing mistake: In the closeups the boy is holding a large leaf of seaweed to offer the stallion. But in the long shots at the waterfront he extends an empty hand with no seaweed visible.