Consider if the gun had been pointed the opposite way when it went off.
Would Trayvon have walked? Most likely, if the jury were fair. After all, no one saw it start. So, no one can contradict the defendant's story.
A lawyered-up Trayvon would have said he was in fear of his life when the creepy ass cracka jumped him and was about to shoot him, except he grabbed the gun and twisted it around at the last second.
Of course, there would have been a lot of dirt in Trayvon's background, but a good defense lawyer and a liberal judge could keep all that from the jury. So, the jury would come to the only logical conclusion, compassion be damned! (Actually, the only just conclusion, even with the dirt, but we have to consider low-information probabilities.)
Of course, one major difference: you wouldn't have heard about unless you lived in Sanford and were a local news junkie (most news junkies are not local news junkies).