His height is being used as evidence, because Zimmerman is 5'2" tall. Outweighed Martin, but seriously shorter. 6'3" Slimm was on top of 5'2" Zimmerman beating the snot out of Zimmerman's face, and pounding his head into the ground. Sounds like self-defense to shoot "Slimm" in that scenario.
I didn’t know Zimmerman was 5’2”. At that height, if he weighs 240 lbs. (100 lbs. heavier than Martin), he probably isn’t in the best condition physically.
But, that doesn’t mean he didn’t start the confrontation. He might’ve been cocky because he knew what he was packing. His size and shape could explain why the teen got the best of him, though, in the physical fight.