Obviously I need to be sensitive and I wasn't in the aircraft so I am providing second hand information, but that said I understand that the;
a) Governor was engaged and operating "correctly" - however it can't always keep up (this is also true of high altitudes in the R44 - so I'm told)
b) Rotors were oversped and needed NDT inspection and new spindle bearings.
c) Aircraft was normal weight with passengers - in a Clipper that normally means near-ish MAUW as there's a weight penalty for the float system and often we don't fill both tanks to stay within limits with four up.
See;
Overspeeds | Aeromega Helicopters
CC