Dennis,
Looks like your 'dan undu'! , in which case you probably need to check what the deal is in OZ. In the UK, generally employers require a Disclosure Certificate for employement purposes, which is basically just a criminal record/background check. We also have a whats known as 'spent convictions' in terms of the Rehabilitation Of Offenders Act. ie. aftr 'so many' years, depending on your convction and the offence, your record will be 'spent'.
By the sounds of it however, you were not convicted of anything in court. You were obviously charged and the case went as far as a court appearance but that appears to be the extent of it. By the looks of it, the judge admonished you i.e. no case to answer! Your mate on the other hand may not have been so lucky. Best check with your local Police and they should be able to give you some paperwork to apply(for a fee of course) for a crmiminal record check. Thats certainly possible here in the uk.
As for it affecting your flying career, I would doubt that very much.