While I largely agree, I still don’t fully agree. He should have treated it as loaded because it’s a gun, but I also understand why he didn’t. There are many dangerous facets in our lives where we trust professionals, like doctors and pilots and chefs. Professionals that count on other professionals doing their job and keeping the whole system running.
You can extra prepare, and argue that everyone should at all times, but its also entirely reasonable that we dont run background checks on pilots or breathalyze them before they get onto a plane. We expect the system to work for many dangerous things, and it almost always does. The fact that it almost always does is part of the issue here, because believing the armorer was doing their job to keep people safe is a reasonable assumption.
Should he have applied extra caution to checking that gun? You bet. Do I think he was complacent because of the systems they had on set for gun safety? Yes. Do I think that rises to murder or even extreme negligence? No. It was a lapse in judgement that ended with him killing a person, and that is terrible, but not criminal.