Thanks fantom, what you describe here is called
weather deviation and has nothing to do with
Strategic Lateral Offset Procedure SLOP to which Captain Bob was making reference but not knowing how strictly it applies.
Finally someone to consider that the AF447 crew was
maybe not that blind or careless, but trying its best to avoid weather, like already did LH507 20 minutes before them, or IB6024 and AF459 12 and 37 minutes after them.
I really would have loved seeing the BEA stating that critical point instead of writing the erroneous following comment :
up to the last automatic position point, received at 2 h 10 min 35 s, the flight had followed the route indicated in the flight plan