Who reduced the Thrust from TOGA to Flight Idle for a few seconds near the top of the climb, when the pitch of the aircraft reduced, slightly ?
Then TOGA was restored, for the all that remained of the flight.
PF held/ had held a French Gliding Licence from a few years earlier. I do not know how active he had been or still was. A Brevet "B" only required a couple of "S Turns" and a safe landing. I imagine ( but I do not know) that our PF went well past this level, to Brevet "D" or beyond...
(AF encouraged some former members of Cabin Crew to become Pilots - our Captain had been one, earlier in his career.)
The PF could have become a gliding Instructor. He probably would have had aero-tows with the cable fixed to the nose of the glider. This would have given him enough height to practice stalls and spinning. He would have been winch launched, sometimes, where the cable might be fixed lower down, perhaps under the Pilot's seat, to get the best height possible, rather like a kite.
Underslung engines have an effect on the pitch of an aircraft, normally advantageously " more power=nose up..... less power= nose down"
At this moment, for AF447, the nose ought to come down.
Someone else said that only Nostradamus would really know what was in PF's mind. But who did alter the Thrust, twice?