Yes, I remember watching the AN124 display at the RAAF Richmond Airshow in 1988. It looked to me like it was tootling around at about 30 Kts!
I would have thought it would be a relatively easy exercise to have it thrown out of court without an excessive waste of time.
I would have thought that it should not have got to court in the first place. However, the same pilot is, on my understanding, also being prosecuted for operating contrary to the aircraft's AFM - in excess of VNE - on the basis of groundspeed recorded on the ground and forecast winds. If that's correct, my view is that these prosecutions are, at best, based on a 'fail' standard of BAK and, at worst, a deliberate 'hatchet job' by people who know full well the kinds of tolerances and margins of error of the equipment and variables involved but have chosen not to explain that in detail to the CDPP. However, I hasten to reiterate that there are always at least three sides to every story. Perhaps there is some 'smoking gun' evidence in the form of, for example, a qualified pilot who was also in the aircraft at the time.
Your point about strict liability is a stark one in the circumstances of 'low flying'. It's a strict liability offence. A diligent pilot operating a serviceable aircraft can inadvertently breach the minimum height rules and it's still an offence. Easy example: VFR aircraft with an altimeter that 'overreads' by 50' and everything else is 'perfect and accurate' including the QNH. Cruising at 500' 'indicated' over the sea is actually only 450'. Strict liability offence.
Ironically, when all the tolerances and margins are the other way, a pilot could decide to do a 'beat up' at 250' indicated but actually be 500' above the water!