The Talmud asks: "Is a lunar eclipse a sign of evil for Israel, or the enemies of Israel?" Rabbi Judah answers: "when the student hated by the teacher sees the teacher go for the whip, he knows for whom punishment is intended." It is patterns that build recognition and shape response. To remark that it should not be so is foolish. Why the belief in the rule of law and the need to uphold it, except for the belief established by pattern that this is superior to mob rule?
Even if it were merely that "stand your ground" laws do all the harm that opponents warned -- it would be enough. But it is a convenient escape to blame a poor law that allows such things and such verdicts.
What invites mob violence is the belief that the system is invariably rigged against a particular distinct class (or in favor of a particular distinct class) or is so random that it does not constitute justice. When mob violence starts to look better to a sufficient number of people, the rule of law breaks down.
It is easy to focus on the single conviction and say in response to the above: "So should Zimmerman be convicted even if he were innocent?" But that misses the point. It sees only the crystallizing event, the pebble that started the avalanche, and ignores the long, slow build up in the countless cases that preceded it.
As for myself, I simply observe that how one reacts to the Zimmerman trial and acquittal is shaped in part by what you fear. It is useless to explain to anyone here why he or she is "wrong." The avalanche has started. It is too late for the pebbles to vote.