One day while helping him with an inspection, I spotted the queen and showed him. Big fat queen. "She's on this frame", I said. Nope, he couldn't see here. I tried to move the frame to dead center as she walked on the frame I kept moving to put her directly in front of Bobby's noise. Nope. This had been going on for months. A I took the frame with the queen on it and we moved away from the colony. I asked him if he was comfortable removing his veil. He was. He did. AND then eureka! We figured it out. It wasn't that Bobby wasn't grasping the differences it was that he couldn't SEE the differences. The mesh of the veil was blurring his vision. I see the queen! Oh look at that drone! That's a brood frame! We both were so relieved and so excited but then.......Bobby put his veil back on.
The next time I helped with an inspection I arrived to find the new and improved veil Bobby made. He took a $50 veil and cut it. But a window in it! VIOLA!