"I can't see the CO of 5Avn being any more keen to waste a couple of his helicopters and crews than a RAAF CO would have been."
From one who has been on the greasy side of those things (81-89 repairing avionics for USMC), it all depends on what the definition of "waste" is... and on one's definition of "acceptable risk" and "possibility of success", now doesn't it?
The commander whose men are the ones in dire need of the "air support/medevac/lift out" is probably going to rate their risk a little heavier than someone else's aircrew's risk, while a "different service" commander loaning his aircrew and helo out to aid someone else's men is likely to reverse the weightings.
The Army commander is not disregarding the safety of the aircrew even a smidgeon (in his mind), he just has a greater sense of urgency about his own men's needs.
This is NOT usually a deliberate, conscious decision... this weighting mostly happens on the subconscious, emotional level.
This is simply a fact of human nature... you care more about those you know personally, or who you have been given specific responsibility for.
Does this mean the ground commander is more correct... or correct more times?
Not necessarily, but as the one "on the ground", you feel more comfortable relying on the commander "in our own service" than that "different service" commander.
Once again, a subconscious, emotional level thing more than a rational opinion based on experience.
You may have great support from "those other guys" 95% of the time, but one bad experience (or one mis-percieved as bad) can outweigh dozens of good experiences.
I do know that both the US Army and the USMC ground elements feel & claim that Army rotary-wing and USMC fast jet & rotary-wing air support is pressed more closely and persistently than USN & USAF air support is... correct or not, that is what they feel.
Thus an Army in command of the ADF wants the helos on the "Army's team", right or wrong.
Of course, the aircrew are now "his men" as well, now aren't they... so the same dynamic will keep him from "wasting" them, won't it?