As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER A 1.5 HOURS FLIGHT, CREW SHUTDOWN AIRCRAFT AND NOTICED OIL LEAKING FROM UNDER ENGINE COWLING. DISCOVERED STARTER HAD SEPARATED FROM ADAPTER BUT HAD NOT LEFT THE ENGINE COMPARTMENT. DID NOT HEAR ANY STRANGE SOUNDS DURING THE START OR THROUGH OUT FLIGHT. SEARCHING THE PARKING SPOT WHERE THE FLIGHT HAD ORIGINATED STARTER PARTS WHERE FOUND.