Just watched the video.
You don't shoot someone dead for grabbing your popcorn and tossing it at you, which appears to pretty clearly be what the deceased did.
You don't.
That's not a threat to your life. Popcorn tossed in your face is not a threat to your life. It is not an indication that any threat to your life is coming on the horizon from that person, either. You're in a crowded movie theater with people all around. The guy is with his wife, the guy just told you he'd been texting his young daughter.
This man has a family. This man is someone YOU started shit with over texting DURING THE FUCKING PREVIEWS NOT THE FILM ITSELF. So, you start shit with him, he loses his cool and grabs your popcorn and tosses it in your face (he should not have done this no matter how big of a dick you were being, granted) and you fucking instantly whip out your pistol and end his life? Depriving his wife of a husband and his daughter of a father... over some popcorn in your face?
Fuck that shit. Completely, totally, 100% unacceptable and anyone who would argue that the law should support that needs to rethink their position. That's the kind of assertion that makes the elimination of all reasonable self-defense statutes more likely, because it paints those of us who believe in self-defense and SYG as unreasonable and crazy.
It's like with the Trayvon thing. If Trayvon had merely punched Zimmerman, and did nothing to get on top of him or follow up from that punch with anything further, I would not support Zimmerman having shot him. It was the prolonged restraint and beating as Zimmerman screamed in terror, all seen by a disinterested witness, the injuries, and the seeming complete unwillingness on Trayvon's part to cease the assault, which made me support that.
The Jordan Davis thing was much less clear. But if he made legitimate verbal threats which were convincing, that he was going to kill Dunn, I could see at least the first few shots. That was a tricky one.
Popcorn in the face from someone you'd been dickish to, justifying ENDING THEIR LIFE? Holy shit, not in a million years. I don't even think that would rise to the level of management kicking him out, maaaaybe... maybe kicking you BOTH out.
That's the kind of shit which results in you saying to your wife "man I can't believe that asshole threw popcorn in my face" on the car ride home, not the kind of shit which results in someone dead and a little girl without a father for the rest of her life.