Am I liable for work done on a house, that I requested, if the work was done 4 months later and after the house sold and transferred to another owner?

My house was in contract with a buyer who wanted roof repair as a condition of the sale. The roofer was told verbally that the work needed to be done as a condition of a sale and that I would proceed only when Earnest Money was received. In August when the EM was in escrow, I authorized the work. The Buyer canceled the purchase contract in November as he couldn't obtain financing. I had no communication/contact from the roofer at any time after I requested the work. The work was not done when the Buyer canceled the contract. Subsequently the house sold and transferred to a new Buyer. I did not specifically cancel the roof work. I received a bill from the roofer that work was done in December, 20 days after the house transferred to a new owner & 4 months after I OK'd the work. I was never contacted to schedule the work or check if it still needed to be done before allegedly doing it. Having no access to the house after selling it, I have no proof work was actually done. Am I liable?