Defaulting buyer recorded contract with county

[Jeff Conway]

So i had buyer 1 that was supposed to be cash deal, never sent pof, it was supossed to be a quick sale 2 week close. After 1 st closing date they asked for extension 3 days( granted) then another 2 days (granted) and after that i declined any more extensions be ause they never semt pof, always getting excuses from their agent. After that he would sign mutual cancelation agreement, i had another cash offer and took it since contract with them was dead even though they tried to revive it. I closed with buyer 2, deed was recorded, and 5 days later appears the contract from buyer 1 recorded with county, I never told them propertt has been sold and kept threatening litigation when they breached contract to begin with. What can happen now? Can they sue even though they breached and not me? Contract states time is of the essence. I didnt have to extend anymore closing dates according to my contract.