Condo in escrow has lien, what should be done?

[Mark Hu]

We are in escrow, and have learned that there is a reverse mortgage on the condo in escrow.
The buyer assures us that he has enough funds to cover anything debt over the purchase price. We are of course concerned that he would sell it even when he owes more than the sales price. If it turns out he can't sell it, what recourse do we have besides pulling out? We've already paid for the building inspection, appraisal, and may have other costs.