I don't think it matters that is was an accident, even if the police saw it. Anez should have been tried for manslaughter, at the very least, even with the cop reporting it as an accident. Their glossing over someone's murder, which by way of the narrative, Power Girl is partially culpable for, leaves a very bad taste in my mouth.
Knocking over a bolt, scaring someone with a gun, and having that person shoot off someone's head is not light and breezy comedy. It can be comedy, very similar to what you'd see on Drawn Together, but it's not what I expect from a DC hero. It's sloppy for someone who's supposed to be good enough to be in charge of the JSA, specifically the JSA training the next generation of heroes.
It's nice for you, and apparently the majority of Power Girl readers, that you can be okay with Power Girl being a humorously direct part of a bystander's death, but that's not what I want to get out of a comic book about Power Girl.