The police don't come up to your car at will and open the door to go through the glove box on a suspicion you might have something of interest in there.
They do, you know. That's exactly how the Police find drugs, stolen property and illegal weapons. They have to right to stop your vehicle at any time and carry out a search - IF they have a reasonable presumption that a crime has/is or could be/is being committed.
However - it's a big jump from a CASA inspector to a Police Officer. The CASA inspector does not have the same powers as a Police Officer, because Police are sworn officers of the Crown and have powers of arrest.
A CASA officer is merely a Govt official with modest powers to carry out inspections relating to aviation regulations. Despite what many Govt inspectors will tell you, they do not have the same power as Police.
They are not authorised to enter private property and search without permission. They
are authorised to enter workplaces and areas where operations that fall under their jurisdiction, operate.
Accordingly, a CASA inspector has the right to access an aircraft sitting on a Govt-recognised airstrip/aerodrome.
There are many Govt inspectors who abuse their power and position, and an arrogant and "pushy" Govt inspector is just what we all don't need.