Here's the scenario:
You live in a small gated community that has a rash of break ins, you're out taking an evening walk. You observe someone you have never seen in the small community walking and looking at the homes. You follow them to see what they are doing. You call the police while they are en route the person approaches you and try's to take your gun away. What do you do?
I may be missing the point, but Zimmerman was in his car. Seems like a vastly different scenario.
Just for grins, and as you have some LEO experience, say you're the responding officer to this situation. You're coming up on it knowing only what you see: a non-responsive subject on the ground, a subject standing nearby who looks like he's been in a struggle and has a handgun in his hands. He volunteers that the shooting was in self defense. What do you think and what do you do?
Honest question, mostly for my own edification.