I'm just a passerby here, yes, what happened was a tragic accident, whoever was in charge of props should be held accountable for incorrectly handling the gun.
At the same time... Alec should be held accountable as well. He didn't know the gun was loaded, yes, but he still killed someone. That cannot be justified or denied. If it could, then we wouldn't have tens of thousands of articles reporting on the incident. I assume he'd just flash some money around and walk away like nothing happened, because actors are always above the law. *cough* Amber Heard *cough*
If this occurred away from the set, and it was just a bunch of ordinary Joe's mucking around with a prop gun, and misfired, I'd assume there'd be a huge inquest into the crime, and the person would be charged with manslaughter. But hey, if an actor commits a crime, its okay, cause he cried a few tears and is cooperating with police. I kinda doubt he'd take responsibility of the incident, or acknowledge the reality of the situation. No way in hell would he be willing to be charged, if there will be any.
Just a tragic incident overall, just kinda miffed people are in denial over the gravity of the situation, instead of solely honing in on the props crew, blame also lies elsewhere with the actor that actually killed someone.