So Trayvon is such a master of kung fu that he turns the tables on an armed man who gets the jump on him, pointing a gun at him, but having pinned his armed attacker to the ground and rained blows on him, somehow completely fails to disarm the man at that point, or even protect himself from the weapon.
This is the thing about this case. The Trayvon fans are completely unconcerned about reality. That's just not a realistic or probable scenario, and any honest person would see that.
The alternative scenario is quite realistic. Trayvon initiates an attack, pounds Zimmerman to the ground, and Zimmerman in a panic reaches for his weapon and shoots Trayvon. I do wonder if Zimmerman is lying about Trayvon going for the gun, but it doesn't really change the scenario.
Trayvon attacks Zimmerman. Zimmerman, after a taking a beating, pulls his gun and shoots Trayvon. Consistent with all known facts and common sense.