I live in NC too. I say the same thing. Nothing really defines what a medical exemption is so there is nothing stopping any individual from saying they have one. It's the confrontation people want to avoid though so most just put on a mask instead of calmly standing their ground.

I understand some mask nazis can get very aggressive. My wife will break down and put one on if someone really pushes it. This is what they rely on though. You don't even have to push back per say. Just don't give an inch. People are emboldened to yell at complete strangers to comply. Do not allow them to. It just gets worse if you do. Would you give in to a screaming toddler? Treat it the same way.