The warning shot followed a grab for the gun and an extremely aggressive advance up into his face. All he did was stand still. That's not becoming an aggressor, and neither is holding a gun. Legally this has been done to death, you're not required to let yourself be killed because someone else has an emotional reaction to seeing you posess a gun.Sure, but that wasn't the question Tombs was answering. He was asking how do you know he wasn't in fear for his life.
That's not true. Particularly if the "defender" legally became the aggressor at some point and lost the right to self-defense. Self-defense is also not the only reason for a legal shoot, preventing a forcible felony, etc. I think the 'warning shot' muddies the waters a bit but that it's still a legal shooting.
I've not cared enough to dive that deep into Texas law, but warning shots appear to be deadly force there. If the initial warning shot were deemed to be unjustified, that's enough to at least start down the road that shooter became the aggressor at that point. I still think it's more likely than not to be a 'lawful but awful' shooting, but that makes the argument less certain.