Uh huh. I think you're just being racist because the children who were acquitted of the crime were white. Where's your outrage over those kids in Mexico City who were beaten to death because they dressed like goths?
I know the concept must be confusing, but up here in countries where the government and courts aren't run by drug lords we have a person called the "prosecutor." It is the prosecutor's job to prove the guilt of the people accused of a crime. The prosecutor failed to do so. Furthermore, even the prosecutor agreed that the victim started the fight. That's the reality of the situation you are ignoring.
What would you, Mister Kung Fu Master, do if a white guy attacked a group of your friends? How far would the extremely Mexican you and your equally-Mexican friends take it? If you were drunk, how much control over the situation would you really have?
More importantly, what would it say about the victim's character when you goaded him into a fight by calling him "cracker", "gringo" and "white trash"? Why, if I had the ability to think without bleeding profusely from my very Mexican eyes I would probably conclude that the person was a hot-head with a history of violent behavior, given the fact that he wasn't able to keep control over his temper when faced with a bunch of racist children. Hmm. A confusing concept, I'm sure!