Okay... Clarity on the actual law is needed here.
Hypothetically speaking, in 1986-1992 you could have be fined $10,000 and/or serve 6 months imprisonment as an individual under the Western Australian Environmental Protection Act. This never happened to an individual with a decat...
The above act has never been applied to any automotive circumstance. (Well, non that have been publicly reported)
A review of the act in 1992 see's penalties based on a 3-tier system with fines/imprisonment determined on a case-by-case basis.
I've simplified it to an extend to highlight the conjecture about certain 'facts' in this thread. Obviously, it is much more elaborate and circumstantial but has no bearing in this instance.