There is only one question here. Did Zimmerman have the opportunity to retreat and avoid serious injury or possible death once Martin was on top of him beating his head on the ground? If the answer to that question is “no”, there is no crime here.
By the way, the answer to that question is “no”.
The author missed two points I would have liked him to touch upon. First, stand your ground laws often protect the person claiming it from civil suit. Second, the prosecution may decide to say that Martin was employing stand your ground protection from Zimmerman because Zimmerman appeared to be a threat to Martin thus making Martin afraid for his life.
p>
I’d wish this first point would protect Zimmerman, period. He shouldn’t be civilly liable regardless if he could retreat or not. Regarding the second point, I wouldn’t put it past the prosecution to pull such a stunt.