takata
2. Air France longhaul crews are composed of the "commandant de bord" (captain) and two fully qualified co-pilots (F/Os) having the exact same rank (whatever their age).
3. When captain is leaving the deck, he should decide whilch one of his two F/Os will be the pilot in charge (PIC) during his rest.
This is where I believe the Air France way of doing things is fundamentally flawed. Most other airlines have a distinct chain of command, Captain > Senior First Officer > Junior First Officer. In this case the older, more experienced first officer should have been "In Charge" while the Captain was resting. [This would not prevent the Junior FO controlling the flight and making tactical decisions but may have encouraged the Senior FO to be more assertive when things were not going so well.]
This may have resulted in a better outcome !