The onus is also on you to demonstrate how anything Zimmerman did could in any way have compromised his legal right to self defense.
So far you have posted absolutely nothing regarding either of these.
And remember, the law does not operate under the principle of 'guilty until proven innocent' for some very good reasons, even if you do.
If I (God forbid) attacked anybody who has a gun and he shoots my ass, I should be prepared to accept (assuming I’m still around) that he may be able to construct a reasonable legal argument that he did so in self defense (I’m 6’5” 270lb).