Is this story an attempt to defend Trayvon Martin, the teenager shot to death by a vigilante a few weeks ago? No, staggeringly, it's actually the story being told by the vigilante's defenders. They argue that Martin attacked Zimmerman, after Zimmerman followed and confronted Martin. They say Zimmerman was in the right because Martin was able to fight back, and may have thrown the first punch.
We don't know if the story is true, but one thing is for sure: if your idea of a right to self defense is that a scared young man shouldn't be able to fight off a stalker, but a lucid stalker should be able to shoot a scared and excited young man who has managed to get the better of him, then you have a very strange idea of what self defense constitutes.
Florida has a "Stand your ground" law, a law I reluctantly support. I think, on balance, it's better that someone who has a legitimate fear of being attacked be able to use force to defend themselves, than for them to have to worry about going to prison for doing so. While it may not feel like something necessary in a civilized society, the reality is that not everyone is civilized, and the fact someone might defend themselves is itself a deterrent against those who aren't. Moreover, it's simply inhuman to say that someone scared, whose judgement is going to defined by their fear, should not be able to use the tools available to them to defend themselves.
Stand Your Ground was attacked by some because they saw it as the catalyst for Trayvon's killing. They may be right, but not in the sense they argued. Their argument is that Zimmerman thought he had a legal right to dispense justice because of that law, an argument that's almost certainly untrue. Zimmerman clearly wasn't threatened until (if he was) he took a lucid decision to involve himself in a confrontation. Trayvon clearly never got an opportunity to make a lucid decision. He felt threatened, and he (if the story above is true) stood his ground.