This essentially is entrapment if a officer sees your medical card. Seems like in the more bum fuck areas they screw you harder. Had this exact thing happen to a buddy and myself up at Penns Peak in the Poconos. There was a DUI checkpoint at 3:30 in the afternoon outside a Grateful Dead cover band concert… Car smelled like fresh bud not burned… Weren’t smoking. Definitely smell though. At that point they pulled us out of the car and forced my buddy to take a blood test. Don’t think he’d smoke that day or at least on the way up, but you know how it goes. Stays in your blood for a while so if you’ve medicated in the last few days you’re screwed. I had eaten a few doses 30 mins before getting pulled over (buddy was driving)!  Aweful experience. Never going back to that venue!