A classic example of CASA not being consistent is "Aerial Baiting"
Before 2003 an operator had to have an AOC and aerial baiting on the AOC as an aerial work function before the operator could drop baits from either an aeroplane or a helicopter.
Then in 2003 by an Aviation Ruling, it was deemed to be a private operation. This meant that one could drop wheat laced with chemical as baits for mice (aerial baiting) on a private licence, but one needed an AOC and an ag rating to drop the same wheat without the chemical in it if seeding.
When Part 137 became law, it required an aeroplane operator to have an AOC and the pilot to have an agricultural rating to drop baits.
But a helicopter operator still did not need to have an AOC to do aerial baiting.
So one could have the situation of an operator who operated both aeroplanes and helicopters dropping the same baits, but requiring an AOC and aerial application function on the AOC for the aeroplane operation but no requirements on the helicopter operation. Both a helicopter and an aeroplane could have been dropping baits in the same area on the same day but with completely different requirements.
So what to do. That is easy, just rescind the aviation ruling. Remember this was legal advice in the first place that decreed aerial baiting as a private operation.
Now the legal advice is that aerial baiting requires an AOC.