As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, ENGINE NR 2 OIL QUANTITY INDICATED 0. AIRCRAFT RETURNED TO DEPARTURE AIRPORT. GROUND MAINTENANCE FOUND OIL LEVEL FULL AND NO OIL LEAKS NOTED. CANNON PLUG ON TRANSMITTER WAS FOUND OVER TORQUED WHICH CAUSED PINS TO UNSEAT FROM RUBBER GROMMET. THE CANNON PLUG PINS WERE RESEATED AND CANNON PLUG REINSTALLED. OIL QUANTITY INDICATION CHECKED NORMAL.