The ATSB really should elaborate on why the conrod actually broke. Instead they've left a lazy comment that reads 'The engine failed due to a broken conrod'. A life of operating at 70% power at 50degROP and climbs conducted at 25/2500 took its toll on this engine. As Lumps mentioned, these engines are very strong thats why most of them last but you'll get one that doesnt (100HTR, nearly buddy, nearly!) and it ends up becoming involved in a completely avoidable accident.