In fairness to CASA, the Blackhawks they were talking about have reached their 'life of type' so far as the ADF is concerned, were designed to standards of which CASA was not and perhaps is not aware and maintained by reference to ICA of which CASA was not and perhaps is not aware. Plonking a qualified test pilot in the seat doesn't address those issues.
Having wrested the rotary wing capability and expertise away from the RAAF back in the early 90s, the Army flew the Blackhawk like they operate tanks.
Here is some relevant reading. If CASA wrote to Sikorsky and the FAA about early model Blackhawks that have been flogged by the Australian Army and reached their 'on paper' life of type, and asked: "Whaddaya reckon about their airworthiness?", I reckon the response would not be very informative.
All of that said, not being able lawfully to use a functioning helicopter to carry properly-informed emergency services personnel in a state of emergency due to a firestorm is silly.