Nonsense. Zimmerman thought Martin was black, and he said so at the time. He was correct. He then stalked him, despite Martin having every right to be there, and not doing anything illegal. That initiated the fight. And that is not in even the remotest way any sort of "proof" that Zimmerman was not motivated by what he thought was, and what actually was, Martin's race. There's not the slightest reason to assume that had Zimmerman "thought" Martin was white, he'd have even followed him.

You have a very bizarre concept of what constitutes "proof" that racism was not a motivation in Zimmerman's actions that night. All that we actually know is that a crime by Zimmerman against Martin was not successfully proved to a jury of Floridians.