Your husband sounds like a good guy. And a sharp guy.
I am wondering if Michael was just so into himself that he didn't notice her behavior. That, or the fact that he worked nights and she worked days and they hardly saw each other in the last year before she collapsed.
Well, my husband is in the military, so he worked a lot of crazy hours and was frequently away from home. But he is very perceptive and sensitive. (Don't tell him I said that. :-]) And I doubt that Michael was.