As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON PILOT PREFLIGHT INSPECTION IT WAS DISCOVERED THE RT ENGINE OIL FILTER BYPASS WAS POPPED, THE OIL FILTER WAS REPLACED, AND OIL SAMPLE TAKEN. IT WAS NOTED THE THE REMOVED OIL FILTER WAS DAMAGED WITH MATERIAL MISSING FROM THE FLANGE. WE BELIEVE THE FILTER WAS PLUGGED FROM THE MISSING MATERIAL OF THE FLANGE AFTER ENTERING THE OIL PUMP.