Can a mechanics lein be filed against my property?

I'm a property owner in KY who had a building on a property that had been condemned. I was given a certain time period (days) by the county to have the building removed or there could be a fine for every day I was in violation. I spoke with the county agent who originated the notice who gave me extra time to have something done with the building before taking action. I set out to hire a contractor to tear down the building and remove debris to comply with the order. I found one contractor who did give a quote to do just that. I advised that I did not want to put that much into the property and wanted to shop around for a more reasonable quote. The quote was $4500. The contractor asked what I was wanting to get out of the property if I sold it, and I answered $11,000. He indicated that he might be interested in buying the property and if I would take less if he removed the building. I advised that I would, and that I would take off $4500 from the price if he removed the building for a reduced total of $6500. He advised he would take it at that and that he would get me a down payment within a month. I did not hear from the contractor after a month and some time later a friend sent me a photo showing the building being torn down. I assumed the contractor I spoke with was going ahead with his work and that I would receive a down payment soon. Later, I received a phone call from the contractor stating that he was finished with the work and that he had purchased a trailer to place on the property already, but realized there was no septic service to the property and that there was a propane tank discovered on the property that would have to be removed with the necessary environmental red tape and expenses. He advised due to all that he was no longer interested in the property. I advised that I had made no guarantee that there was septic service to the property and that there was gas and water, and that he could always install a septic system on the property and get an inspection to be compliant. He advised the he now would not take it even if I gave it to him. Then he brought up the quote of $4500 that he had made earlier and wanted paid, insisting that I had requested him to do the work. ( I had not). I advised that I had not contracted with him to do the work, only that I had agreed to sell him the property at a reduced price as there was a building that would need to be torn down to comply with the county order, and that I would still uphold my part of the agreement to sell him the property at a reduced price. He finally advised that he was not going to be hoo-dood on the deal and that he would file a lein on the property and that I would never be able to sell it. We ended the conversation and I received a letter from an attorney describing a mechanics lein for the $4500 for improvement to the property plus fees, etc. I have not received anything from the county pertaining to the lein. No paperwork such as an invoice or a work order was inlcluded with the lein nor was any such paperwork ever signed by me or ever submitted. Where do I stand with this property? What should I do from here? It has been several months since the letter was received from the attorney by me. Any advice would be greatly appreciated!