Called 911? She needs to know what to do! And that is not it... If he went too low, she needs to give him the gucagon pen... If you talk to her, ask if she has one of those around the house for him. I have never gone so low that I have passed out, I've been 26 and in the 30s a couple times, but she needs to give him the shot for suger when he is low, then call 911. And most likely, by the time they arrive he will be awake to greet them at the door. Otherwise, it just takes minutes depending how much insulin is on board for him to drop too low...
Scares me when I hear stories like this about diabetes, because I know one day, that will probably be me... But I think with modern tech, I should be ok... I hope...