Buyer Wants Out

Red flag!  As a real estate licensee (salesperson, broker?) you are in danger of overstepping your field of expertise and could end up in trouble no matter how this all comes out.  At this point you should definitely advise your clients to consult the best real estate lawyer they can find.  If they don't have a lawyer, don't  take on the responsibility for "recommending" an attorney.  Instead, provide the names of several lawyers you know who handle real estate and urge  your client to choose one immediately.

If your license is as a salesperson, in most states you are under the supervision of a broker, who should of course be alerted to the problem right away.  An experienced broker will have advice, but I hope it's to -- stay out of it.