There is no legal obligation for you to identify yourself to any businesses that I'm aware of. Most businesses will refuse you services if you refuse to cooperate in paying, to the extent that they are legally able to do so. I think you can expect that a hospital met with this scenario will complete their obligations under the EMTALA and nothing more.
Even with identification, healthcare systems usually will not do more than they're required to under EMTALA. The hospital will provide intensive care to the uninsured DKA patient, since they're obligated to do so under EMTALA, but they will not provide that patient the insulin and other care necessary to prevent them from needing ICU in the first place, since it's not yet an emergent condition.
If there's no risk of criminal exposure, even insured people should start doing this. Hitting hospitals with uncompensated care under EMTALA is one of the few points of leverage we have to fight back against these murderers. Hospitals are, by and large, not innocent parties in this -- several hospital groups are even members of the Partnership for America's Health Care Future terrorist group, which bribes politicians to fight Medicare for All.
It would bring me great pleasure to get to tell a hospital to go fuck themselves and to quit bribing politicians to fight M4A if they want to get paid next time.
If I'm dying, I want the best care I can get. I'm not about to argue with someone trying to save my life to make a political point to an ER doctor who didn't have anything to do with it in the first place. And I'm certainly not about to risk my own health outcomes by withholding the insurance that I paid for to help me in that exact scenario.
Oh, I wouldn't be arguing with the ER doctor. I'd be arguing with the billing murderers, like the one that comes in to shake you down for money while in the ER bed.
