Hopefully some NC residents will chime in, but to the best of my knowledge unless they have RAS or PC of a crime no they can't stop just to check your license.
"Just say no."
Of course, they could then invent a reason... oh, yeah, we saw you weaving... you didn't signal back there... or [crash] your taillight is broken.
Out of curiosity, did they just glance at it to be sure you're you & the license is current, or did they actually run the license # or your name to see if you had any warrants, etc.?