How will CASA know whether you have a clearance or not? We only keep the audio tapes for 30 days and they can't just be replayed willy nilly.
As to CASA calling it a violation, that's exactly what it is. A Violation of Controlled Airspace, a VCA. How do you know it was a "minor infringement"? Do you know what other activity was going on in that piece of CTA at the time?
Airservices doesn't care about the enforecement side of things because that's not our job. We do care about trying to keep you out of airspace without a clearance because it's a safety concern. ADS-B would allow us to make directed broadcasts to aircraft before they penetrate. The number of times I've made blind broadcasts to a VFR pootling along right through the middle of an active firing area and received no response. Maybe if they shot one of you down you might pay more attention.
A while back I noticed a pair of unidentified VFRs absolutely nose to nose at the same level. One happened to be squawking a code other than 1200 so I made a broadcast referring to the code. The pilot piped up and apologised for not squawking 1200. Fark! He was less than a minute away from having a head-on - I couldn't give a toss about the code, just turn!
C'mon shagpile, get real. Next thing you'll be telling people not to make radio broadcasts for fear it'll be correlated to a radar return.