because there's nothing to suggest that zimmerman identified himself to trayvon or that trayvon had any reason to beleive he WASN'T in danger.
All the details being argued over (who was on top, who threw the first punch, whether or not the fight was on grass, whether zimmerman was following trayvon or returning to his car) and the attacks on witness credibility, it's a dog and pony show that's just meant to confuse everyone and muddy the waters. The gaps are hazy, but it seems like Trayvon was under assault, and that at no point did Zimmerman attempt to identify himself to Trayvon and diffuse the situation, meaning that Trayvon was still, legally, under assault when the physical violence broke out, and if he was being assaulted, then there is no way, shape, or form, that zimmerman has a right to self-defense. In fact, it is Trayvon, not Zimmerman, who can defend himself here, so Trayvon would legally have the right to throw the first punch, or to pummel zimmerman to his death.
This trial is full of red herrings.