I don’t know if a tattoo is legally binding. But if you have a DNR, there can be something very minor, and they can put you down.
He’s also done all the living will paperwork. But as he said, EMTs never see paperwork, they see your chest. Anything that’s got you needing resuscitation isn’t minor. Yeah if they bring you back maybe it wasn’t a big deal. Unless you got brain damage before they brought you back. I’m not saying everybody should take his path, I certainly haven’t, just saying he knows the math and made his call.