I dunno, if you're in charge of rescue operations, and see a person holding on by their fingertips to the side of a massive cliff, and instead of helping, you just drive by, I'd say that's passively killing someone. Ignoring your job, that would have saved someone's life, and you chose not to. This is what health insurance companies do thousands of times every day.
Luigi actively murdered someone who was passively responsible for thousands of deaths.
Seems more like a real-life version of Dexter to me.