Arm out the window:
Yes, but what do you really do, in the real world?
In the real world one does lots as I have had to do with venture (vulture) capitalists.
1. Immediate ban by industry and associations on consulting or cooperating with CASA. One achieves this by a polite refusal to consult stating that you "fail to understand" what it would achieve. Be aware that if CASAs mind is already made up, all you are doing by consulting is providing them a fig leaf in the form of diffusion of responsibility for the regulators actions.
If consultation is unavoidable, ask for a written and prearranged agenda. Prepare your own position paper, present it, ask for questions, stick strictly to the agenda and then leave. Refuse to engage socially except for a cup of coffee.
2. In dealings with CASA beyond simple submission of forms, ask for a lawyer to be present and permission to record the conversation.
3. Do not engage in the show cause process as has been explained by others.
4. Apply political pressure using the mantra "jobs, investment, growth" as in "how will this (action by regulator) affect jobs, investment and growth?". Repeat this mantra at every opportunity.
If everyone does this without exception, CASA is effectively in coventry until it demonstrates by its actions that it is dealing in good faith.
To put that another way, pretend your next door neighbour is a venture capitalist who will sell your children into slavery if given half a chance.