While I agree with what you are saying above, maybe I'm misunderstanding part of it? I don't think that carrying a weapon is necessarily always foreshadowing. That would mean that every time someone goes out with a weapon they intend to use it. If a person was going to a bad side of town and taking the gun in case something happen, I wouldn't consider it foreshadowing per se. Just like this guy took the gun over because he knew it was a party and anything could happen... Now in this case I think he took it over to make his words louder and is guilty as shit but I hope you can understand where I"m questioning. I guess if he's out waving it around you have a point.
Its one thing if he brought the gun but wasnt brandishing it. Its a party of adults for what looked like a 50 year old female teacher, and a fucking fire captain, that doesnt really come off as a situation where a guy should have to fear for his life for asking them to tone down the music. Its not like he was trying to break up a party in south central full of crips.
This guy created the situation and worse yet, looks like he killed someone that really didnt have anything to do with the actual altercation. I dont recall a female voice in that video threatening to get her gun and shoot him, but most definitely a man did, so he even shot the wrong goddamn person.
Its completely another situation where death would be avoided if hed let the damn cops do their job or just grin and bear it, YOU KILLED SOMEBODY OVER LOUD MUSIC, WTF.