As I've never flown mustering, and I don't claim to understand the interpersonal and political angles regarding CASA and the mustering industry. However, Frank was quoted as saying that 90% of the accidents occur in Oz, and Oz only accounts for 10% of Robinson sales. Lu brings up some good points about constant cyclic adjustments; that may be a factor and it is most likely the main difference between flying characteristics in mustering and other endeavors (training, private flights, etc). Seems like mustering would have a much higher percentage of hovering and air-taxi operations than most.
Design limitations?
Documentation discrepancies?
Policy management?
Pilot education and training?
It sucks that the honest folks are getting the brunt of this discrimination.