OR, it may make the enclosure way too hot. It doesn't take much to heat a 10 gallon tank.
Either way though, an accurate read on your temps will fill in a lot of blank spots, even if they don't give definitive answers on why he regurged.
Personally, I don't think ANY pet store has ANY business selling animals when they can't provide clients with proper husbandry education. Also...for future reference...when taking on the responsibility of a live animal, not only should you make sure you're well informed of their husbandry requirements, you should also make sure you can afford and already have in place all the proper equipment needed for their care...all this BEFORE you bring the animal home.