Yep, I know one of those (now ex) husbands. His wife was in a serious car accident, in a coma for several days and eventually came home to recuperate. She recuperated well but they split up after a few months.
Two weeks after she moved out, he told her he was with someone else...it was pretty obvious he'd started seeing her before the official split.
One neighbour said that "he wasn't used to looking after her, she always looked after him." Well, phooey to that. 
I've lost all respect for him and he knows it!