i saw this as well , it made me think that maybe the RAN should have gone the way of the RNZN.
The helos were brought from the states as a oin venture between the two goverments. the RAN went for the upgrades these were always going to test the technology that was promised on these Helos.
the RNZN went the way of Zero hours on the airframe, after working on the airframes and hearing the stories from the guys at SAFE air in New Zealand (sub contracted for the Airframes upgrades)
It would not surprize me if it was the airfames that might be the problem with the RAN helos, if i am wrong i would be intrested in hearing the reasons why the Helos were grounded for.