This accident was caused by extremely unexplainable pilots behaviour, which at the end of the day we will never be able to really understand why. It was so much against everything sensible, you can not plan, predict or prevent it technologically.
Indeed ... this may be inexplicable ..
The fact is that the BEA has investigated whether this behavior was explained (or induced)
He did not give a 100% satisfactory answer but gives in its conclusions and recommendations a few tracks