My FIL was a very manipulative, mean, SOB. We are all, frankly, relieved that he didn't have an accident while driving and hurt someone else.
MIL and FIL have been handling the legal stuff very well--MIL has Power of Attorney. I think they're doing OK with the emotional aspect too; he always told them they would fail UNLESS they did "it" (whatever "it" was) HIS way. They're finding that the world does indeed continue to revolve without him directing every aspect.
I hope I do not sound cold saying this, but I have put up with his "stuff" for more years than anyone should have to.
From your previous posts about him I thought that there might well be a sense of relief