Certainly bordering on the criminal. According to some ex-colleagues of the offender, he wasn't reported to the authorities eventhough KAL found out about the incident when the aircraft returned to Seoul whereby another outbound crew found the damage. They retrieved the QAR recordings and found the culprit. He was grounded for a couple of weeks, sent for ground debriefing and had a couple of simulator sessions before released back on line. It was done hush hush by KAL in house without the KCASA or JCAB alerted as that would probably incur a huge fine for the airline. All well and fine for that miscreant and his airline. HOWEVER A HUGE HAZARD for other operators who ran the risk of hitting any FOD resulting from the engine pod prang leading to something fatally damaging! He must be well protected by some higher ups for the company to risk that!