I hate to be devil's advocate, and I do not necessarily back up PetSmart or PetCo, ... but, if there were 6 or 7 babies, and only one was emaciated, then isn't it probable that he just refuses to eat?

Which, as we all know, ball pythons have a tendency to do, so it would not (necessarily) be the fault of the store. I know they are not being kept in the best of conditions, but pet stores are going to keep animals in cramped living quarters. It's business, as much as I hate it.

Employees there are given very little training on reptiles. I used to work at a PetSmart and knew next to nothing about snakes or lizards. The managers didn't know, either.

My advice would be to calmly, and nicely, explain, "Hey, I noticed one of your snakes has a stuck shed. That can be fixed by simply making the humidity higher, and giving him someplace to soak in." (The watered down version will be best, since I doubt they'll listen very closely) I wouldn't take the non-eater if I were you. I would just suggest to her that if they isolate it, and give it more places to hide, that it may eat better.

Don't be mean or rude, and offer simple solutions to their problems. More than likely, they'll be thankful for the tips which will keep their profit alive.