Other mistake: Jim Lampley reacts to a knockdown by saying "That could be the end of the fight right there," then quickly adds "but no!" when he sees that Rocky is getting up. The problem is, we hear the "but no!" just before we see any sign that Rocky is going to get up.
Other mistake: Prior to the fight, it showed the champ at 33-0 with 30 KOs, but they stated pre-fight that he has never been the distance in any of his fights.
Only the ref can stop a fight. If a cornerman throws in the towel, that won't stop the fight unless the ref decides it does indeed need to be stop. When the ref stops a fight early, that's recorded as a KO for the winner's ring record.