Pilot Position induced errors.
Having watched the discussion on the 777 at DXB accident, I wonder if the Piloting Position (at the front of the plane.) could have been a contributory factor. The Static Vents and Pitots are also located up-front.
So although the front is going up, the wing may not be climbing, and the rear of the plane is actually descending.
I had a working Vertical Speed Indicator (VSI) in my car, and can confirm that even a change of height of 5-10 feet can give a large positive reading.
By pitching 15 degrees nose up, the flight crew would initially feel as if the aircraft was climbing, unless they could fly the aircraft from the rear seats, in which case their initial thoughts would be that they were descending.