He had every right to shoot the guy. Absolutely no shred of doubt. They were ganging up on him, TELLING him they were going to kill him, then hit him on the head with a skateboard (lethal weapon used like that). These people are professional rioters/looters/terrorists. They are NOT regular protesters and do not behave like regular protesters. They are VERY violent and do no back down. You have to train someone to do that. This is an insurrection, a revolution and should be treated as such and the leaders arrested, prosecuted for treason and they should be executed.
Someone here at FR posted this undercover video a few days ago. Describes and exposes the protesting as being highly organized, even connections with US leaders like AOC and others:
https://www.youtube.com/watch?v=oUCTtrVUTU0&feature=youtu.be
They give training sessions in hand to hand combat and encourage their protégés to poke the enemys eyes out. That was in the latest Project Veritas video.