Absolutely. It's the fact that it was allowed to escalate despite previous concerns that makes it so shocking. When done properly, it would have been prevented. And theoretically, even if the armorer could continue with her work, would she even want to at this point? I have my doubts as it would weigh heavily on her conscience, and from the sounds of things, she would likely not want to be in charge of anything. I mean, if she had doubts of being ready before this, this is not going to convince her.
From what I understand, they were rehearsing. What that entails regarding guns, I'm not sure, but I would assume the actor would be going through the motions, possibly depressing the trigger if the scene warrants it, under the assumption that the gun wasn't loaded. Somewhere down the line, he was told the gun was cold when it was handed to him, when in fact it wasn't.