"I suspect he's going to have to give them the money back."

In the US, if two parties owe each other money, it can sometimes be handled as a suit and counter-suit. I.e. one case for both debts. At the end, a balance might be calculated in favor of one party. (Larger debt minus smaller debt.)

This says nothing about the present case though, particularly given differences between jurisdictions. It's just a general observation about these types of cases.