As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 6029 - IAD - FLIGHT CREW REPORTED FO DV WINDOW NOT CLOSED IN FLIGHT. CREW PERFORMED AIR RETURN AND LANDED UNEVENTFULLY. IAD MX FOUND DEBRIS ON THE DV WINDOW TRACK. MX REMOVED DEBRIS AND PERFORMED OPERATIONAL CHECK SUCCESSFULLY. ACFT WAS APPROVED TO RETURN TO SERVICE.