Test for "no retreat" laws
The article describes it as a test of "Castle Doctrine," but it's actually of the "no retreat" law.
What is a bit annoying is that I've seen plenty of cases on these facts (attacker, with evidence of aggressive intent, defender testifying that he fired because the car was coming at him. All involved law enforcement, and no charges were brought. Here, the guy was out walking a dog, the survivor agrees that they were coming back to get the defender, and had rounded up another guy, a gang leader, to help in the work. Whether the defenders were LEOs or civilians, I think a murder charge is outa line. Of course, as with any trial, you have to wait for the evidence to come out.