It's extremely rare when I come across a pet store employee who actually knows a thing or two about bettas...
I went to Big Al's and looked at all the bettas and one of the employees just came up to me randomly and started lecturing me about their dragons- how, with dragons, it's "all in the fins". What the heck are you talking about??!!
Whereas, when I went to PJ's to get Damon, the guy there actually told me he kept his betta in a FIVE GAL and told me he had one in a community tank of 20 GALLONS with all the right fish, etc.
In the hobby for 9 years.