I’m so sorry, Zamboni. It was good of you to reach out to give him that normal conversation & connection when it was possible, & you did all you could to help your family to stay connected. It sounds like he had compassionate attention from at least one of the nurses present, too.
I don’t know if it would give you or your family more peace or less, but there’s a chance that nurse may act as a reporter even now if there’s context of possible interference in his healthcare she has suspected or been aware of. The coroner’s office may also be able to provide guidance on how to report concerning circumstances.
Whether you decide to contact either of them or not, I hope you can reconvene as a family, without interlopers, to remember & take comfort in what others remember.
What I’d probably have wanted to know, possibly less applicable: There’s no longer any need to make pleasantries or feign normalcy & that makes space to actually grieve in the open & with family what it sounds like you had to grieve in advance in relative private until now. You did as much as you could to protect him. To the extent that you had to compromise yourself to do that in this hostage situation, now you can attend to your own emotional safety again. You’ve been through a lot you had to suppress for others but that actually makes it more tiring rather than less, because it’s twice the effort to operate in two realities at once, & sometimes that bill comes due suddenly. Rest, actively. Take a page from cultures that prize inserting joy into observations of bereavement if yours doesn’t, at least in private, whatever small joys feel appropriate, especially things you shared with your dad. Draw your friends in if you can, as well as family, they will want what is best for you which can be healing on its own & a reminder of what you had to ignore for so long.
Condolences & wishing for peace for you all.