How do you propose, in the middle of a medical emergency, to identify the people who have been excluded with enough speed to deny them expensive care but not harm the chances of saving someone who has not been excluded?
You have 4.5 hours to treat someone for a stroke and 6 hours for an MI. Not that you don't have to go quickly, but you also don't have to rush unnecessarily.
There's not a lot of running down halls in screaming in real ERs, but there's also no time to, for example, send someone to go home and get the ID the patient forgot in their panic and hurry, to prove they're not blacklisted "no medical treatment" somewhere.
So it seems reasonable to simply tell him that the next time he comes in he has to be active in a program to improve his general health otherwise he gets booted once he has been positively identified unless he can pay himself.
Anyway it seems that one of the consequences of what the doctor did was that he lost weight and improved his diet -- I would want to see much more focus on that and none at all on the touchy-feeley stuff.