If his lawyer filed a petition to make your friend a ward of the court or state then he'll need an advocate to ask to take custody of your friend. A blood relative would have a stronger case for being assigned to his case.
When in a nursing home they will attach any assets to help pay his bills. They could be using his disability to take control of his assets. Time is crucial.

Most states will pull your licence after a seizure. Usually for 6 months

under what authority is he being held against his will? has he been deemed unable to care for himself by a court?

Get a good lawyer ASAP! They will take everything they can get their greedy paws upon, if he's isn't careful!

Can you advocate for him?
Maybe file a police report or contact an Ombudsman
It sounds fraudulent to me.
You friend needs some help here.

You need to get him out of there because these facilities try to keep them for a certain amount of time because then they can gain access to all of his assets