I think that the subject is all wrong. It's not really all that unbelievable.
My local pet store when I first started in ball pythons didn't know how to sex, and didn't like probes, because they said it would sterilize the snake.
After building a relationship with them, they began to let me sex their snakes for them and even show them how to. I didn't mock them or make fun of them, and I purchased most of the adult females that were dropped off there by people who no longer wanted their snakes (this was in 2005/2006 when breedable normal females were still selling for over $1000 online).
I didn't however, ever take one of my own collection into their store. Anything I purchased from them went straight to QT into a PAM treated tub.
I would never do anything as risky as exposing any of my collection to a variety of pet stores just to prove a point, but that's just me.