Ann Coulter on Stand Your Ground Laws and the George Zimmerman Case

I thought that Ann Coulter made a valid point (or at least a point that deserves consideration) about the Stand Your Ground law on ABC This Week (see the transcript here).  (Of course, I'm not a lawyer, but she is.)  Ann was essentially disputing the idea that the shooting of Trayvon Martin had anything to do with the Stand Your Ground law, which states that, when you defend yourself, you don't have to retreat but can stand your ground and use deadly force against your assailant.

For Ann, the Stand Your Ground law is irrelevant regardless of which narrative you accept.  In the narrative that George Zimmerman was following Trayvon Martin and then shot him, George Zimmerman is doing the stalking, so of course he's not retreating.  He's the aggressor.  In the narrative that Travon Martin was on top of George Zimmerman, George Zimmerman cannot retreat because he's unable to get up.  He can claim self-defense in that case, even apart from the Stand Your Ground law.

This makes a degree of sense, but I wonder if possible complexity within the narratives could make the Stand Your Ground laws relevant.  Regarding the first narrative, suppose that Zimmerman was following Trayvon Martin and Martin responded by fighting with him, placing Zimmerman in a position where he'd have to defend himself.  Could Zimmerman claim self-defense, when he (Zimmerman) started the conflict by following Trayvon Martin?  Regarding the second narrative, was Zimmerman always on the ground?  Was there never an opportunity for him to retreat?