As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW CALLED WITH LEFT ENGINE OIL QTY READING ZERO. APPROX 5 MINUTES LATER, PRESSURE STARTED FLUCTUATING PLUS OR MINUS 10 PSI. CREW ELECTED TO SHUT ENGINE DOWN. ENGINE WINDMILLED FOR APPROX 10 MINUTES. MAINTENANCE FOUND THE MAIN ENGINE OIL FILTER O-RING CUT. REPLACED FILTER AND SEAL.