Your "facts" are incorrect.
Zimmerman was not talking to 911 dispatch. He had called the non-emergency number.
There is no evidence that Zimmerman continued to follow after being told that it wasn't necessary (mind you he wasn't told not to do it, just that he didn't need to).
When Zimmerman hung up with the dispatcher after telling said dispatcher he would meet the police by his truck, Martin was closer to his home than to the spot where he was seen attacking Zimmerman.
Zimmerman's wounds and the dispatch recording all corroborate Zimmerman's story.
all sorts of evidence released to public domain for each person to listen to and form their own opinion.
just like you I've got an opinion and it happens to be different from yours....
judging from the MASS protest going on around the country ... there's a good chance there's other folks out there that also disagree with your opinion.