I think if someone could look at the facts, there's no way to determine what Zimmerman would've done without a gun. I also believe Zimmerman thought his life was in danger when his head was buzzing from being hit into concrete and he felt like he was drowning in his own blood.

Ed, if Martin were on his way home, why did he put himself at risk of the unknown, when it was shown he had plenty of time to just go home and eat his candy. Maybe he was unnecessarily suicidal, and George was duped into assisting.