I actually saw this same thing in the ball python enclosure at a local store. Of course I could blatantly tell that some of them had an RI because some of their mouths were open and could just tell something was wrong (when some of there mouths were closed it still looked a little ajar). Ball pythons are the only snake I have seen them do this with though. All the other enclosures usually have 2 tops in each enclosure. Of course they have a $1,500 female spider in its own enclosure without a hide. A lot of the snakes there actually have their own enclosure they just always seem overstocked with ball pythons.

edit: the guy I talk to in the store doesnt know much about ball pythons other than that they are shy. He really doesnt know much about how to take care of them from talking to him. He basically takes care of them like he would a boa (he used to breed boas).