You can only sue them for this if they acted in a knowingly wrongful way--i.e. filed the claim knowing (or if they reasonably should have known based on the facts available to them; that is, they can't rely on "willful blindness" to save them) that the claim was false; in that instance, you could potentially claims for defamation and/or tortious (i.e. wrongful) interference with economic advantage. But the law does not punish people or businesses, or make them liable, for in good faith filing or bringing claims even if they turn out later to have been mistaken.