Exactly. Not only was she overpowered and deprived of her weapon, but she broke procedure as well. Why didn't she just hand him a hacksaw and save herself some trouble?
I don't think she meant for this to happen. I think she, like many people, broke a rule that she was casual about.
Why, I don't know. Maybe someone went out for coffee or something and rather than make him wait, she went in. Maybe he had been very nice and pleasant.
Who knows but I am not going to pile on her, she got a GSW to the head and will have to live with dead people because of this.