If this goes to trial and it comes out that Trayvon instigated the fight, so be it. But for now, we just do not know what went down, yet it is stated over and over that Trayvon punched and/or jumped GZ. That may or may not be true but until we know for sure it is irritating to see statements to that affect that are not followed by IMO, JMO, MOO, or what-have-you.
That's all JMO.
I don't know that we'll ever know for sure. There aren't any impartial witnesses to the beginning of the physical fight that I'm aware of.
What we do know, is that GZ was carrying a gun and it seems highly unlikely that he would begin a physical fight with his fists if he had a gun in his waistband.
I'm left with the only other conclusion - Trayvon started it.