I saw something similar happen in San Diego a while back. This guy pissed off another guy, then started walking away. The pissed off guy, and all his friends, ran after him. They started beating him across the street. Then, all of a sudden, the whole group dispersed and started running in different directions. Turned out the guy being beaten had a knife and stabbed one of them. As soon as that happened they all ran off, leaving their buddy bleeding on the side of the street.
Lessons Learned:
Don't piss off a guy with a bunch of friends.
If you do, there is a good chance they are a bunch of pansies who only fight because they have numbers on their side.
Carrying a knife is a good idea.
Your buddies may not be as good of buddies as you think.
I will refrain from any derogatory jokes containing the words "bean" or "burrito" in reference to the ethnicity of these particular hoodlums.