I totally understand your opinion, but I have some issue with your analogy of a girl at the bar.
Rittenhouse didn’t illegally take a a rifle across state lines just to have a good time or to go shooting with mates, he took it to go into a riot to act as a form of riot control. While the girls presence was a passive agitator to the men (in the sense that merely her presence was enough for them to harass her) Rittenhouse was an active agitator as seen in videos where he acts as opposition to the rioters. He is also well outside of any police lines and in an active part of rioting.
This isn’t a debate about the legitimacy of the protests, it’s decent into rioting or anything to do with BLM, it is simply: Kyle Rittenhouse, with careful preplanning, positioning, and active counter-participation created a situation in which people were going to react aggressively to him.
If you follow your girl at the bar scenario, the girl would need to travel out of state to a dodgy and dangerous bar, get right besides the bad guys in the bar and interact with them in a way they wouldn’t like, then finally have a situation in which she would need to use a firearm. Therein lies the debate if that’s murder or not.