I knew a guy that was into collection Hotwheels.
Apparently, every carton or case has a special collectable in it. It may be just a certain different color or something.
He would pay an employee to hide a couple cases until he came in. They'd go to the back, pullout the case, open it.... and he'd grab the one he wanted.
It wouldnt surprise me if something similar was happening. Pay an employee to keep some boxes out of view until he comes in to buy.