Some big black guy (football player Rashad Bobino)suckerpunched a woman in the face, then a 150 LB Roger Huerta jumps into action: "You just punched a f**kin' girl," Huerta is heard saying. “F*ck you, f*ck these bitches, I’ll knock out any f*ckin’ bitch that I wanna f*ckin’ knock out, I’ll knock your f*cking bitch ass out.” - said Rashad Bobino

At 00:44 into the video you can see shirtless Roger running after the attacker and 10-15 seconds later you see the attacker (the black guy in a yellow t-shirt) lying unconscious on the ground, covered in blood and surrounded by people who were trying to help him.

According to some sources the guy who punched the girl is Rashad Bobino - a former UT football player. He is playing football in Austin for the "atxfl" (www.atxfl.com)

You find out the detailed description here:
http://withleather.uproxx.com/2010/08/roger-huerta-beat-up-rashad-bobino