I agree that he has no recourse at this point besides bugging the hell out of you. He could try to take it to court and even if he won, it would not even cover the court costs that he would incurr, however I don’t think there is any chance he would ever win in court especially considering you told him what you thought was wrong with the car. It’s not like you said the car was 100% mint and had absolutely no problems. If that were the case, he may have a reason to be pissed, but even then, if it is not in writing, there is really nothing he can do.
private sales are implied AS IS unless otherwise stated. f him
lil late but i thought id throw that in