They are supposed to use hand sanitizer after being in the tanks at chain stores, at least. And to them not washing their hands in between tanks, most stores will have all of the freshwater tanks running on one loop and all of the saltwater on another. So, if anything is in one tank, it will eventually transfer to another. Granted touching any dead animal and then proceeding into another tank is simply retarded and she needs to be fired. You never directly touch anything that is dead. Doesn't matter if it's a fish or a dog or whatever.
I wash my hands before with warm water, but never after. I've had fish water splash in my mouth, algae, my floating water lettuce, fish food, etc. I quit caring so much. I just do some hand sanitizer.
The TB that fish get is a separate strain from what we consider TB (such as what killed off most of Poe's family), but still in the same family and is not the easiest to transfer. It is also easy to cure in the beginning stages and since I am frequently have to watch my health (recently became a vegan/gluten-free), I don't have the strongest fear. It's obvious for the most part too, skin rashes and severe itching.
Now, my gecko on the other hand, wash thoroughly before and after wash everything, including taking off any clothing he touched (he jumps all over me), and do a good scrub with hand sanitizer. I also then jump in the shower. I haven't had him long enough for the most dangerous diseases to be caught and luckily I got a CBB. But, still, reptiles carry much scarier and stronger things that transfer much better and fully to humans than fish. His cage gets cleaned out as well as I can and thankfully for me, I have a gecko who prefers to use the rest room in a particular area that he never goes too.