It seems that I've become my local shop's resident fish watcher. :P
Yesterday I went in and noticed that two of their bettas were covered in fungus. This is unusual for them, typically their bettas all look superb and in relatively good health. So I pointed this out to them nicely (they said it had been going around and they'd already pulled others off the shelf that same day for treatment) and went about my business.
Today, I was back in the same area so I decided to pay the bettas a visit and see if they'd gotten a shipment in. As I was looking around, I noticed that one of the betta cups was empty. I located the occupant on the top of the container. He had managed to jump two inches into the air and through a hole the size of a dime, and was now beached on the lid. I thought he was dead, but he jumped out of my hands when I took the cup off the shelf. So I plopped him back in the water. Poor thing. He wasn't dehydrated or even sticky yet, so I must have walked in and noticed a few minutes after he got out.
So that's three fish in one shop in roughly a day and a half. :/