Hi,
Plenty of companies have a "one leg each" policy, one leg the captain is the PF, next leg the F/O is the PF.(and is the correct way in my opinion)
This is in no way restricted to Air France.
As I write before is not a big debate to have now.
It's just to know that a problem can exist about the flight deck duties at the time of the event.
It will be different when all this will be in the court of justice
Lawyers job.