This post is correct, self defense doesn't apply when you create the situation and put yourself in danger on purpose. Classic example is you can't walk out into the middle of the street and then shoot at cars for trying to run you over
But there is a video of the kid before the shooting. He claimed to work at one of the businesses (kid lived 17 miled away, people saying he lives out of state is true but is a bit misleading to make it sound like he lives further than a daily commute) and be there to defend it. He said his primary purpose was that, and to apply medical aid to anyone the protestors attack, and showed his medical bag. He said he had the gun in case he needed it for self defense.
I think that post is following the narrative that he lived very far from the area and went hoping to shoot people. Maybe he did, but if it comes out that Kyle did work there, its going to be hard to prove he was lying about his intentions