I agree with EXDAC.
Your logic, werbil, is that, by definition, any flight training during a flight review has to be conducted by a Part 141 operator and, also by definition, the "operator" of any aircraft in which flight training during a flight review is occurring is that Part 141 operator. I don't think that's how the definition of "operator" works.
Para (a) of the definition of "operator" depends on whether the operation of the aircraft is or is not authorised by one of the mentioned certificates. It doesn't dictate that flying training can only be conducted by a Part 141 certificate holder. Is all that flying training being conducted in RAAus aircraft and gliders etc happening in aircraft whose operation is authorised by a Part 141 certificate?
More fuel for the 'ICUS' debate!
It would be interesting to know CASA's current view on these questions.
Completely concur with this:
It is critical from a safety perspective that there is only one pilot in command at a time, and everyone understands who it is. If there can be a change of PIC during a flight, how and when that change will occur has to be very clearly defined by the operator so that there is no confusion as to who is in command at any time.