As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WARNING LIGHT FOR LOWER AFT CARGO DOOR ILLUMINATED AFTER TAKEOFF. DUMPED FUEL AND RETURNED TO DEPARTURE STATION WITH LIGHT EXTINGUISHING WHEN LANDING GEAR EXTENDED. INSPECTED DOOR WITH NO DEFECTS NOTED. CHECKED AND ADJUSTED DOOR SWITCHES PER BAC MM 52-71-00 AND OPERATIONAL CHECK NORMAL.