I still say if the guy threw something at him first, which he clearly does in the video, then I think there is room for the stand your ground defense. As dumb as it may be, throwing something at someone is assault. It's an old guy, so it's felony assault. I think standing your ground in the defense of a felony assault could fly.
I still think they need to alter the SYG law to make it legal if flight isn't possible. That would have gotten Zimmerman, since he followed & confronted before he stood his ground.