What I quoted are edited lines from the bankruptcy code. Cornell.edu has the code available online but I don't believe it is updated with the "new" changes.
Your problem may be that his petition lists the debt as an unsecured claim rather than priority. Then it would be up to you (and your attorney) to prove otherwise.
See his bankruptcy petition or more specifically his schedules to see where the mortgage debt is listed. Your atty should have a copy.

