As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5639 - DURING CLIMBOUT OF CVG RECEIVED A CABIN DOOR OUTER HANDLE WARNING. CREW DECLARED AN EMERGENCY AND RETURNED TO THE FIELD. FLIGHT LANDED WITHOUT INCIDENT. FOUND CABIN DOOR NOT FLUSH WITH FUSELAGE, PERFORMED OPERATIONAL CHECK OF DOOR HANDLE, NO DISCREPANCIES NOTED.