I think someone “borrowed” the gun to play with it, and left 1 live round in it when they returned it. Then I think the armorer picked up the gun, didn’t check it fully, assumed it was empty, and started putting dummy rounds in it from her full stash. I think she didn’t keep count and didn’t notice that she only put 5 dummies in.
So, yes, I think Baldwin may have only fired once, but Hutchins lost her involuntary game of Russian Roulette. This type of accident is extremely rare on film sets, so it’s very likely that a long chain of unlikely events had to happen to make this tragedy happen.
I think the young woman’s social media profile suggests she doesn’t have a rigorous enough intellect to even be trusted to fill your order correctly at a McDonald’s drive-thru.
I've seen the difference between .45 blanks and live rounds. You can't mistake one for the other. I think someone else put bullets into that gun unless evidence to the contrary comes out.