Z's shown a lot of bad judgment since the shooting, but I don't see how anyone faults him for this. Had the Martins, et al, not tried (and mostly succeeded) in ruining his life over a case of self-defense, he wouldn't be able to auction off his gun for many times over its market value. And he probably needs the money. It riles up the White* Lives Don't Matter thugs, but what doesn't?
The guy's been dealt a pretty raw deal in life. Whatever his intelligence level, or other character traits, he was trying to help out his neighbors that night. Good for him. We could any one of us be smarter and more cautious than George, and still get dealt the same hand. God help us if it does.
*Or Hispanic, either, apparently.