Not knowing any history, it sounds as though "he", whoever he is, is attempting to cover for the fact that he's in failing health, mental and physical. Are you a relative? Aide? Tell us more. Does he have dementia?
You have the EMT's take him to the ER for xrays to be sure there are no fractures. Otherwise this is a game to him. They really hate going to the ER, they think they are going away for good.
NEEDS a psychiatric evaluation. Who is calling 911? who has poa? do they know about this.? Who is his legal next of kin? If you are working for a company do an incident report and get your management involved.