As the state court lost jurisdiction over the matter when the district court took it up, common-law probate remand to the state court had no basis, as there was no dual jurisdiction to resolve. Also, state court did not have jurisdiction over claim, due to statutory administrative review procedures.
Dissent: Statute requires District Court to remand; District Court has no power to examine state forum's basis for jurisdiction.
http://www.opn.ca6.uscourts.gov/opinions.pdf/18a0134p-06.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.