James
It is not CASA that prosecutes. It is the DPP so CASA's 'history' is irrelevant.
The regulations are about being impaired whilst exercising your licence or authority, etc, not about having had a drink or two and sleeping it off whilst sleeping under the wing. Lets be real. Don't go looking for demons that aren't there.
I am VERY confident that a court will be able to recognise the difference.
ID