Firstly, Luigi Mangione is presumed innocent until proven guilty.
Secondly, there's a fair amount of real evidence that Luigi is being set up as a scapegoat by the NYPD—a police department with a known history of planted evidence.
Second part: I’m not buying that for a moment. It’s way easier for me to believe that an individual working alone, screwed over by a megacorp who earns more based on how many people they can deny healthcare to, had enough and went vigilante. Vigilanteism and cold blooded murder are not OK, but it’s pretty easy to link cause and effect there. That’s vastly more likely than a shadow conspiracy that’s managed to keep its mouth shut so far.
What are people supposed to do? Vote? We voted for the public healthcare guy in 2008 and the powers-that-be decided they would rather back "muslim ban" demagogues than let that happen again.
I get this is your corporate-facing persona so you could never actually speak critically to this point, but the health insurance industry broke democracy, and eventually they'll find out what the alternative is.
But I’ll almost always be against vigilanteism outside extreme hypotheticals (“would you shoot Hitler?”). Even if I were morally ok with a specific instance, some time the person behind the gun might disagree with someone I support, and then where’s my moral ground to oppose their actions?
Edit: Furthermore, as much as I despise UHC and their leadership, I love the notion of our justice system more than I loathe them. When someone decides to be the judge and executioner, society devolves to “might makes right”. I served in Somalia. I don’t want to live there.