if you're an active shooter in a populated place i think you're extremely lucky to get only slightly bashed in the head as normally much worse things would happen to you.

Again, cause and effect backwards here. He was attacked previous to any trigger pulling.

>Again, cause and effect backwards here.

cause - the guy shoots an unarmed man and just coldly walks away from it. No victim check, no attempt to render first aid, no reporting to and waiting for police and emergency services... nothing what is reasonably expected in the situation of self-defense.

effect - reasonable perception that it is a killer on the lose, a threat to defend from.

This is an argument for justifying the following attacks on Kyle. Kyle acting in self defence does not imply that Huber was not acting in self defence.