From the way I read the details, the shooter in question had made a wrong turn of sorts and stopped. His car then became surrounded by protesters, including the BLM fool with a knock-off AK. When said knock-off AK was raised to a high-ready position is when the individual in the car assessed a life-threatening situation and took action.
I don’t know if there was a round chambered in the AK (looked to be Polish...not Russian, but not a shabby weapon) or not. The driver could not know that either, and should assume that it was loaded. I believe he acted appropriately. The fool with the AK may have just been blustering. I love the irony of him being videoed saying “F*ck around and find out.” earlier in the day. I guess it didn’t occur to him that there might be a handgun in a car in Texas.