They won't get much.... The market value of an adult pet dog is practically nothing, and that is all one can claim for it's loss. Value is at most the few hundred dollars they spent for it as a pup.
The best outcome to expect from the story is that the dog is found... returned or reported by someone with a conscience.
FWIW, I don't blame the store employee, who has never been under any obligation to double check ownership of dogs when people ask for them. So everyone, understand why next time, they will treat everyone with distrust.
