Quoting from Boortz what I think is a good take on the SYG part:
As for the SYG law and the Trayvon Martin case, I haven’t seen anyone else bring this up, but both Trayvon and Zimmerman had the SYG law on their side under the three possible operating scenarios here:
George Zimmerman. If Zimmerman was attacked by Trayvon, as he claims, he had the legal authority to use deadly force to repel the attack. BUT .. and this is a big but here .. if he was pursuing Trayvon, as he said he was, the SYG law would not protect him from prosecution. Zimmerman wasn’t standing his ground. He was in pursuit. I see no reason for repeal of SYG here because the law will not stand as a defense for what Zimmerman did. By the way …. I heard Juan Williams on Fox News Channel say – not once, but several times --- that George Zimmerman had been told by the police to stop his pursuit of Trayvon. First of all, there is no evidence that the 911 dispatcher Zimmerman was talking to was was a police officer. Secondly, the dispatcher didn’t say “Don’t do that.” The dispatcher said “You don’t need to be doing that.” Telling someone that they don’t need to be doing something is quite different from telling someone NOT to do something. Williams should understand this.
Trayvon Martin: How would the SYG law stand to protect Trayvon? If Trayvon had noticed he was being followed, and if he elected to flee his pursuer he would have every right to do so. He would also have every right to turn and to confront his pursuer. That would be “standing your ground.” So the rumored testimony of this eyewitness who said he saw Zimmerman on the ground with Trayvon pummeling him does not necessarily implicate Trayvon. If he was standing his ground he was acting within the law.
Now here’s where it could get complicated. What if Zimmerman had ceased his pursuit of Trayvon and retreated to his car. What if Trayvon then pursued Zimmerman to his car and attacked him. Trayvon would then lose his protection under SYG, just as Zimmerman did when he initiated a pursuit. But if Zimmerman than became the pursued instead of the pursuer, does he then have the SYG law to rely on? That’s an interesting question, and one that I think would have to be put in front of a jury.