I though the 0.5*(v1^2-v2^2)=gh equation had been looked at earlier and found to be broadly consistent ?
In the more general discussion, has consideration been given to maximum altitude limitations if turbulent conditions are expected and unreliable airspeed remains a credible fault event which has to be accounted for?
The BEA report indicates that the AoA margin between stable cruise and warner was only 1.5 degrees. Given the coarse nature of the manual inputs it would seem that loss of autopilot precision is at best a serious matter at those altitudes and related/concurrent loss of air speed data and protections cuts one safety rope, then throw in turbulence.....In those conditions it seems that excursions towards a stall are likley even if one could hope that transition to full stall was avoided.