Every pilot starts as a supernumerary
Every pilot strats his/her career from a small a/c.
The Supernumerary would have already flown the larger A/C in a 6 axis simulator and also done a few landings on the actual A/C during a company familiarization flt(Without PAX on board)
On completion of the required hours of Supernumerary flying(which might already have been the case)He would have been in fact officially doing what is alleged to have been done.That is fly from the right seat with a company training Capt on the left seat..and a safety pilot(An experienced first officer)riding on the supernumerary seat.The training sylabus requires the safety pilot only on the first few flts....thereafter if the Capt is to become incapacitated in flt, this same "Supernumerary" till a few flying hours ago is expected to land the a/c safely.So one has to keep in perspective the profesional spirit with which line Capts let rookie first officers fly and build up hands on experience.
While it appears that this particular training was not authorized..hence the punative action.
people need to realize that it is definatly not like the case of the Aeroflot pilot who let his son fly an Airbus 310 ,and could not prevent it from crashing and killing all on board.(due to only one auto pilot chanel disengaged)