The Operator is the one who creates the camera move on a shoot in a way that is considerably to all creative needs and to a given time budget as well. So the operator has to realize quickly and exactly what are the ideas and to find the best possible solution to bring those to live. He has to program the rig and to communicate what are the horizons technically to the director/ DOP and in timing to the AD. So the transitions are very fluid to the MoCo supervisors job while prep and shoot, and this way the operator is his own supervisor most of the time.
But he is also the one who pushes the button to drive and to stop the machine. So he is responsive for serious safety reasons while shooting with robots and has to organize an eye on all things around those the whole shoot. This should be done in an sociable but sustainable manner which keeps a shooting nice and smooth, so this is usually an old- boy- business indeed.