Yes, but the question should also be: cui bono?
In my mind it should be unacceptable that an AOC holder staffs their planes with crew in that way. Okay perhaps for seasonal gaps, but not acceptable as a general 'employment' model. Some ten years plus ago a national authority in Central Europe still required AOC holders to ask permission in each and every case. Later this requirement was dropped, turns out the head of the country's CAA was/is a shareholder of the nation's leading flight crew leasing company that until recently staffed an entire airline.
Go figure.