Do we have a defense?

On the issue of us having to pay medicaid for my in-laws' medical bills looooong after the $31K had been divided 4 ways and spent...the property sold in december 07. My father in law died in december 06. There was a title search done and no leans were put on the property. We had no way of knowing that we owed anyone money. Is there a chance that since there was no lean put on that property during the year and the title search came up clear when we sold it...that we will have a defense?