Being trained to catch fish and KNOWING about fish are two totally different things. Walmarts tanks are FULL of illness, and incorrectly labled fish (which works for someone like myself who could get a very expensive fish for a walmart price if I decided to risk it and actually buy a fish there).
Most employees that work for Petsmart's aquatic section dont even know anything about fish other than how to catch them (and that usually isnt even right) and they know they are told to gravel vac and water change...they arent explained why or anything about a cycle. And this is also why so many of these chain stores stick aquarium salt in their fish tanks to mask the illness and try to prevent it as much as possible.
Personally, Walmart should not be allowed to carry fish. The walmart you work for might be one of the better ones. However, I have a few family members who have and currently work for walmart...and it isnt anyway near what you describe. (and the family members I am talking about have worked for walmarts in FL & IN as well as TX).
The kinds of fish walmart carries is the scariest part.