Some years ago CASA successfully prosecuted a diesel fitter who flew himself to station properties, carrying his tool box, in his privately owned Cessna and on a PPL. They contended he required a CPL and an Aerial Work AOC.
Did CASA actually win a court case or were they just threatening legal action?
I met a pilot who was in a similar situation to the above but caved when CASA threatened him with his license because he and his boss didn't want the hassle of a court case. So his boss ended up driving everywhere in a company 4WD instead of flying in a company aeroplane with a massive loss to productivity.