I thought the boxer’s manager could stop a fight by the act of throwing in the towel.
Is that just Hollywood depiction?
The young boxer most likely wasn’t even aware of his own injuries by the end of the fight and wasn’t even able to make the judgment to end the fight.
You are correct. The people in his corner could have thrown in the towel at any time but they prefer to see the fighter agree, or at least not disagree.
A recent more famous example would be the McGregor- Mayweather debacle. McGregor was getting the crap beat out of him and the referee stopped the fight. Afterwards McGregor complained that he had been in worse situations and come back to win. So you have to walk a fine line. In this case they screwed up.