there is usually a clause in the closing contracts that states that you have disclosed everything to your knowledge regarding the state of the home. If you agree to this clause, any major issues that come up that need to be repaired, the buyer can come after you on the presumption that you had prior knowledge of the problem and did not disclose it. What a lot of lawyers recommend you do as a seller is to offer a sum of 500-1000 dollars say taken off the sale price if the buyer will agree to removing that clause from the contract. Prevents the buyer pulling shit like this after you've sold the house.
That said, for this guy to take you to court and get any money, he'd have to prove that you had prior knowledge of whatever he had to repair and you sold it to him without telling him there was a problem. That means small claims, a lawyer and that shit gets expensive. Possibly more than 2k just to defend yourself.
I would take a close look at your sale contract that you signed and look for the clause i described to see what you agreed to. If it's not there and the contract sais the sale of the house is "as is" i don't think he's got a leg to stand on.