One final thought.
Since there is a mortgage on the property, the quit claim deed might be invalid. It might not be allowed to actually transfer ownership without permission from the lien holder. This would be a matter for state law, and you can also check at the county clerk's office, where the original mortgage lien is recorded and where the quit claim deed should have been recorded.
If the quit claim is invalid and the son still owns the house, this helps with taxes but the father needs to go to court to get himself appointed as the son's personal representative. Again, see an attorney.
