Pulling a gun on somebody after they've got you down on the ground and are punching you in the face for a minute is an act of selfdefense. Logic points to that being the more likely reality than that Martin decided to physically tangle with somebody that already had a gun drawn.
You don’t know if the gun was brandished at that point or not and you do not know if Martin became physically aggressive first. No witness verified what happened before Martin being seen punching Zimmerman, you’re going solely on Zimmerman’s word. Logic does not play into this, you’re speculating. And Zimmerman scaring the hell out of the kid because he was a vigilante, legal or not, was way out of line and contributed to the tense situation. I repeat, I am not saying things did not happen this way. The only thing I would say is that if a 17 year old child was shot dead after walking down the street to the convenience store, I can empathize with the parents wanting a thorough investigation. No one knows and what you believe was likely to happen does not imply facts.