Some guy hits a female in the back of the head (knocking her out), and Huerta returns the favor.
http://www.tmz.com/2010/08/04/ex-ufc-star-in-bloody-street-fight-roger-huerta-austin-texas-video/
http://www.tmz.com/2010/08/04/ex-ufc-star-in-bloody-street-fight-roger-huerta-austin-texas-video/