One of the cons of not using a Realtor.
I am on the opinion that you need to just walk away. Time is the essence, so, you may get a better buyer soon. By the way, you should keep a “second offer” in hand just in case the principal fails to achieve their goal.
" In addition to the obvious expense of these disputes, all of these legal steps create significant stress and take up huge blocks of time on the part of the principals, as well as on the part of the brokers and agents who represented those parties"