Is a real estate contract binding if you have health issues and were forced to relocate to another state?

My brother signed a contract to buy a house in MD. He had two strokes and numerous seizures, and had to relocate to my state (KY) so family can help. He no longer has the funds for the downpayment (not to mention the mortgage). The seller has hired an attorney who wants access to my brother's bank accounts to prove that he no longer has the funds. I do not want to provide any documentation I am not required to produce. Obviously, my brother has lost the earnest money, and can live with that. Can you provide any advice for handling this? Thanks!!