Regardless what he was thinking, that's straight up murder. You sound like you're half way sympathizing with the shooter, which is disgusting if that's the case. I had this opinion reading the story and didn't catch that there was video. Now that I've seen the video, that's damming proof to me.
I suspect this is not over with. Stand your ground laws assume your life was in danger, and that clearly was not the case.
You can't shoot someone for shoving you. The guy made no second advance and even backed away from the shooter. His life was not in dangerous, even if his racism lead him to believe it was.