Between round 2 and 3, Yamasaki went up to Humberto Brown and (in broken Spanish) told him that he crapped his pants, and that if his crap doesn't stay in his shorts, he'll have to stop the fight.
Humberto looked confused and/or embarrassed. I think it might have taken him out of his game, and caused him to look for a way out, to get the hell out of the spotlight in front of millions of people.
Crappy situation to be in
Gag 
Op is right, Humberto's reaction stood out to me but its kinda hard to make out what was said.
well at least a log didnt come falling out of his trunks otherwise the ref would be picking it up with a ziploc
over the roar of the crowd
Humberto! Humberto! You shit yourself man. I said YOU SHIT YOURSELF, MAN!
What's that?
Yeah, I can see it. If you get the gravy legs I gotta call this thing!
I know, Humberto, I get it, but we can't expect this guy to tolerate your shit on him.
Humberto, calm down. It looks like spatter rather than a log, you should be ok for a round.
Sorry, can't help you, toilet paper would be considered a foreign object.
Let's get it on! 
What a shitty situation to be in, and then to have to deal with this crap...
It's either Tap or Snap or take a Crap.
shinbang - It's either Tap or Snap or take a Crap.VU!!!
Cindy
I'm amazed that this doesn't happen more often.
I got in a street fight a few years ago (think it's actually about 6 years now) and I hit the guy with a straight right and he then tried to take me down.
I sprawled and we were vying for position and I must have shit myself. I didnt realise at the time but a few minutes after the fight I could smell shit and the guy I was with said he could smell it too.
It was only when I got back home that I realised a bit of shit had come out. Not certain when it happened but I can only imagine it was in the scramble when we were fighting for position because the rest of the fight was standing and I doubt I would have shaft myself while throwing my hands...
Well thank you Cindy, I'm a poet and didn't know it..same back :)
Seriously though, a very unfortunate thing to have happen.. Unless it was a tactic in which case it didn't work very well..