Not completely unsubstantiated. I've read a number of posts here from people who've pull the plug on parents and grandparents... universally, they come down on the side of George Felos, the right-to-die lobby, and to a lesser extent, their pawn, Michael Schaivo.
I'd say it's more like an educated guess. But then, that's an opinion, too. And no, I don't have any forensic evidence to substantiate it.
Really, who? Please provide evidence to support your allegations.