That section backs up what I mean by "feel threatened." Right now, it's a he said/she said situation. If Zimmerman is being truthful and Martin popped him in the face when Zimmerman merely asked "what are you doing here", then that statute could apply to him.
If Martin's girlfriend is telling the truth and Zimmerman initiated physical contact with Martin, then it could also be reasonable for Martin to fear for his life when a man he knew had been watching/following/looking for him...grabbed him or took a swing at him. Under that scenario, Martin would have no "duty to retreat" could "meet force with force, including deadly force" i.e. taking Zimmerman to the ground and pounding his head on the sidewalk.
All of us are just speculating and offering opinions at this point. Hopefully the police can sort out all the pieces and put together something relating to the truth.
I haven't heard the entire interview with Martin's girlfriend, but I wasn't aware that she said that Zimmerman initiated physical contact.
According to what I've read, she said:
"Trayvon said, 'What are you following me for,' and the man said, 'What are you doing here.' Next thing I hear is somebody pushing, and somebody pushed Trayvon because the head set just fell. I called him again, and he didn't answer the phone."
She didn't say who initiated physical contact.