The only thing I'd do differently is that I wouldn't have chased the guy into the parking lot. I would have blown him away the minute he ripped the cash register away.
How could you not? If you don't kill him, good chance he gets away with your register and comes back to rob you again. If you stop him and recover your register and he runs off, he might come back later armed, especially if he knows you've got a weapon. No sane person would risk his life for this thug.
Nevertheless, these protesters are bunch of hypocrites. Does anyone seriously think they would just let someone run off with hundreds or thousands of dollars of their property without doing whatever they could to stop them? Hell no. Furthermore, if this was a Korean thug robbing a black-owned business and the black business owner blew him away, would these guys be denouncing the black business owner? Hell no.