seller file for bankruptcy help

[Zocky Zhang]

my church is buying a property in MD. 

currently the property is leased to a senior care operator, owner collect 6k rent each month. it has been going for 15 years.
15 years ago owner bought the property with grant from MD State, state said if owner sell to non senior care business within in 30 years, owner need to pay back 500k. now owner still owe banks total 600k.

owner accept our offer in mid july with agreement of sale signed, no contingency on grant waived. He said he will ask MD State to waive the grant, however the grant will not be waived by State. Now owner want to file bankruptcy after realizing sale price is less than state grant and bank loan balance.

will this grant be passed to buyers? shall we sue the owner or someone to carry out this deal without an real estate lawyer?