Just because a shop has a tank with white spot in it doesn't mean it is a bad shop. They may not have noticed it until Travis pointed it out and rightly thanked him for pointing it out. If the tanks in the shop have it, then his should have it too unless they were stressed after his were removed in which case it is quite possible that the fish he bought do not have white spot, even if the rest in the shop do.
If the shop immediately took steps to treat the tank and refused to sell the fish in it, then that is quite acceptable.