the wife bears some responsibility.He shoot him in the back? Hard to tell if he just spun and fell back facing him. Was the deceased trying to enter his house when shot? Was anyone else in the residence? Dumb to shoot the ground first. Heard no threats from the deceased and he did not strike the shooter or have a weapon. Ex wife not concerned she's just talking on her phone standing next to the ex.
Again lucky it's Texas. Most states he would have been arrested.