I know he's been a punching bag, but her taking on those 3 alone is maybe too much

Maybe it happened, the goons weren't with him at the club
I think if she's going with murder Nyx botched the subsequent writing...
It's murder of a HS girl(likely from a family that has money) midtown in broad day light, consequences should be immediate, even a sociopath should be hiding and planning to flee the country.
This happened right after we leave her, 2 days pass after that, our mom should be rushing us to the burial ceremony as soon as we arrive.
Adriana and others also would be aware.
There probably would be peace walks around town and everything.
Even dumbass Zach would get the news...
Also Nyx says a lot of stuff just to get a rise out of people, you need a good filter with her.