I was bent very badly in Cozumel and refused recompression therapy until I returned to the USA 5 days later. That had nothing to do with DAN insurance, but because I was seen by a chamber tech instead of the doctor, who wasn't there.
You are asking specifically about DAN insurance. Chambers understand DAN insurance, and know that DAN will pay them, even if your healthcare chooses not to. It's like having a black AMEX at a chamber. If you break your leg in Cancun, you will have to pay before play, or show your international insurance card. Luckily, a simple fracture in Cancun will cost you about a grand US, so it isn't that big a deal.
When I travel, I carry my BCBS card, a copy of my international insurance policy card, and my DAN card. I also carry a platinum AMEX, because I don't want to pay the fees for the black one. They will take one of the 4 for sure. You will not be allowed to leave the country in many countries until you've satisfied the medical provider. That's a fact, Jack, as Bill Murray would say.
Just curious, is there a trip report or something where you explained what happened to you, what went wrong, why/how you got bent?
Also, anyone know what is a typical bill is for a recreational diver that gets DCS?