It's all speculation.
So is Michael's assertion that Terri wouldn't want to live "like this". I wouldn't want my life in the hands of "my husband" who has already moved on with his new live-in and their two kids. I would want someone who still cared about my well being (which isn't Michael). Most normal people would just walk away and let Terri's family care for her. Why doesn't Michael?! He seems to have a pretty strong will to see her DEAD.