There's a law in that state that says if you are being threatened you are allowed to use force to protect yourself. Martin perhaps should have kept walking, but he didn't half to. If he threw the first punch, then he started an altercation that he only realized was dangerous when zimmerman pulled a gun. At that point I doubt anything could have helped him, because suddenly zimmerman started using that law.I'm saying that it's as much his fault as the other guy's.
If Zimmerman pushed him first, then he started the altercation.
In the end I feel like the teacher, "I don't care who was following who and who punched who first. You're both suspended!"
It's obvious that a series of seemingly innocuous bad choices were made on both sides, and it ended badly. It's not illegal to follow someone. It's not illegal to evade someone. It's not illegal to approach someone. It's not illegal to taunt or question someone. It's not illegal to ignore questions, respond with your own, or get really close and shout at someone.
At some point someone crossed the line, and someone else followed suit and the situation spun out of control. Unfortunately the victor often gets to rewrite history.
While he may have been stupid, he may have had every right to defend himself if he thought this larger guy presented a threat to him. If you're faced with a bigger guy who's been chasing you for awhile you don't pull your punches. You get in, disable him, and get out.
I don't know enough about the case to say one way or the other, but if you're going to speculate that he was wrong, then you might as well explore the idea that he might have had no better choice.