You need to factor in the accumulative nature of the punishment, Horn was dominated and badly hurt in the late stages. Ref indicated in R8 and R9 to do more or he'll stop it, and he walked into even more hard shots, so his teaching career was saved cause it requires brain capacity that was being beat out of his skull. Ref did a fine job actually, allowing some clinching and roughhousing, but splitting them upon butts and more wrestling type action. Good control and solid moment to stop it. Horn had no answers to Bud's finishing shots.
100% due to all the massive head collision opening up both faces. Crawford destroyed horn like every second of every round. Pac had 1 round that was on TC level
How much more punishment did Horn really need to sustain? The fight was long over, Horn was never a threat to win a single round, he was scarcely protecting himself as Crawford was having batting practice.
Were you looking for to horn to get killed? That's the only reason to let it go further. Truth is was a few rounds too many for horn long term health
I actually thought Horn showed a lot of improvement , I had him being ko'ed in 5 rounds but this version took 3 and a half more rounds of beating