At what point id the state become insistent upon which person first verbally confronted who?
Well, aside from the 311 call where Zimmerman jumps out of his car in order to chase Martin - such as at roughly 2:08
here.
There's only one problem. It's perfectly reasonable to confront strangers, in some cases. If I see a stranger in my house, confronting them does not make me responsible for what happens to them. If I confront a stranger in the middle of a martial arts tournament as participants, we're good, as we've both agreed to a non-lethal fight. And if I confront a stranger who is following me around for no reason (I've done this before), then it's a reasonable confrontation.
Zimmerman was following Martin around for no apparent reason, and Martin confronted him because of that. Good for Martin!