Being blackmailed for Release of Mortgage Form

[Levin Angeles]

So I'm selling a property with my Father.  The property was seller financed and the last payment was paid for over a decade ago and we've been using the property for business since.  We've since decided to sell the property and the previous lien is still showing up.  I managed to track down the previous seller and informed him it was his responsibility to file a release of mortgage form and even provided him with a form already filled out for him to sign and notarize.  He has since informed us that it would be too difficult for him to accomplish and that offering him a present would induce him to do what he's already legally obligated to do.

The problem is that we already have a seller lined up and this is the only thing holding up the deal.  The seller agreed to set aside $30k in escrow for this issue and we can go ahead with the sale.  We can also pay this guy off for a tiny fraction of that price to get this done quickly.  Since this rightly irritates me, I'm considering setting aside $30k in escrow then suing my would-be blackmailer for that sum or whatever I'm entitled to.  Naturally that would incur lawyer fees.

On principle I don't want to pay this guy off but as a business it might just be a smart thing to do as a cost of doing business.  Any advice would be appreciated.