The first rule of Fight Club is you cannot talk about Fight Club...especially when Trayvon Martin was a member!

Trayvon Martin knew how to brawl.    That does not mean he instigated the fight with Zimmerman, but it is still relevant to determining whether Zimmerman was justified in shooting him (if Martin was straddling him and hitting him MMA style).

This cases has been presented in a very one sided manner.  Witness testimony supports Zimmerman's version of events.  
Update:  And yes you can kill a man by beating him with your bare hands...