California might actually be the best chance he'd have of getting away with this. California has the broadest "Stand Your Ground" provision in the country. It's the only state where you are allowed to pursue an attacker if necessary to end the threat.
I doubt that will work here. It sure doesn't sound like he needed to defend himself at the point he shot. But it would only be necessary to convince a jury that the threat wasn't over. Outright jury nullification might not be required.
In Washington State you can shoot someone that is committing a felony, which includes them running away from the scene. It would help if the felon had some stolen merchandise on them as they are fleeing.
Texas doesn't need "stand your ground". We don't have to worry about "ending the threat". Here you can use deadly force to prevent the SOBs from getting away. Explicitly allowed. Including chasing the perps down the street.