I must say that I find most of things in this situation understandable.

The assistant shouldn't have given her the keys if it would cause her that much trouble (or for the matter, keep giving rides and then whining about the situation behind her back), but I understand that caught by surprise, you just want to help.

The other woman should have called, but I understand that if her husband was having an emergency surgery, one serious enough to leave him unconscious for so many hours, she wasn't in her right mind.

Now, a woman preferring to stay hours late at work, crying, over going home and telling her husband that she let someone she knows and sees everyday use her car in a emergency situation, that I don't understand