As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING PREVIOUS SERVICE WHEN THE A304 LINK PINS WERE INSTALLED AND LOCKED THE LOCK PIN HOLES WERE DRILLED TO 0.720",MAXIMUM DEPTH IS 0.045". DRILL BIT WENT COMPLETELY THROUGH THE LINK HOLE AND PENETRATED THE OPPSITE SIDE WALL OF THE BLADE CLAMP. UNDER THE ADVICE OF THE MANUFACTURER ALL 3 BLADE CLAMPS ARE TO BE RETIRED FROM SERVICE.