Or why can't there be something about him abandoning his wife to live with someone else?
It's really a kind of bigamy.
Possible in another state, but not Florida.
FL abolished/ended common law marriage in 1974.
It would require the parties to come to an accomodation which would have allowed him to leave and her to be turned over to the parents. The problem is that as husband the law gives him the presumption. As an ex husband he would have an ex wife alive "somewhere". He has an interest in being a widower vs an ex-husband.
The other problem in the case is you have to have lawyers who are willing to reach agreement. Felos gives the impresson of being an absolutist. (ala kevorkian) As an attorney he is not interested in reaching agreement between the parties, he is only interested in setting a precident. (Remember this is senior rich area where family members would have a financial interest in mercy killing which is packaged as right to die.)