Armed with a solicitor I managed to score a Section 10 which means that despite a guilty plea, the Magistrate accepted my defence of 'honest and reasonable mistake'. It also helped presenting a driving record of only five offences over the past 17 years, and wearing a suit!
Thus the offence was dismissed and no conviction recorded. Also the fine and court costs were waived. Now the bad news. The legislation(27) stipulates that the demerit points must stand...
NSW legislation specifies that demerit points must be recorded on your traffic record for all offences where the Court finds you guilty irrespective of whether or not you've been convicted.
Doesn't matter, I'm happy with the judgement which I hope to post a transcript later. After two hours I was out of there and headed straight for a family funeral. What a day.