CASA has treated the airlift component of skydiving as a private operation because CASA considers that the payment made by the parachutists is for the descent from the aircraft, not flight in the aircraft
That's because everyone is required to join the APF as a member prior to the jump - it's included in the price, and you just sign the membership form. As such you are deemed to be a student skydiver, and the aircraft ride is incidental to the jump.