From my somewhat legalist and jaundiced point of view, it would have been almost impossible for any jury following the law and their instructions from the court to convict George Zimmerman of murder. It would have been difficult to convict him of manslaughter. The point is that given exigent circumstances as presented at trial, while he was clearly guilty of homicide, he apparently was not guilty of breaking any law against it.
Unfortunate, but not unusual in our system of injustice often called "the best in the world."
All the other matters matter quite a bit less than the law and the court's instructions to the jury at trial in cases such as this.
Social and political issues are obvious. The way this case is being used so effectively to keep the rabble divided -- against their own interests -- is despicable, but it's working rather well. So long as it is seen purely as yet another example of racism in America, or the impunity of white folks, or what have you, people who should be on the same side against the oligarchs and plutocrats will be fighting it out with one another to prevail in the argument over this case.
We see the same phenomenon in the Snowden Thing, where prevailing in the argument -- whichever one is priority at the moment -- is far, far more important than actually doing anything about domestic surveillance.
It's shark season...