gotta take a fighter's mind into account -- they just went toe to toe bashing each other, and bashing is the only thing that's been on their mind. the guy got up and immediately was in the other guys face. he wasn't threatening or whatever, but the last however many minutes for which the fight lasted, that's all they were focused on. getting OUT of the bashing mindset is easier said than done.
agreed on the reffing part -- he wasn't thinking, and the most important part of his job is boxer safety. he blew it, and the poor guy probably won't ref again.
edit: i just watched the video again -- watch the arms of the guy that got knocked down after he gets back up and approaches the other fighter. they shirk up like he's about ready to move, so i really can't blame the guy standing for clocking the **** outta him. if he even was aware that the fight was over, when the other dude walked up and shirked up his hands like that, i'd have done the same thing.
that is, if i was a good fighter.