Well Airbus manuals would say that wouldn't they.(about pitch attitude & height)
However if you take the guidance out (Autopilot) at 40,000ft on a 332 and wait.. The a/c TENDS to climb. Tried it a few times on different days as was interested after I knocked the disengage button on the side stick button with our ungainly hard plastic tech log.. Noticed the a/c was STARTING a gentle climb.
Whatever, I still believe that an attitude indicated indicating 16 deg NU. At height would look weird to any heavy jet pilot. If that 1.6 g spike is true that probably explains the INITIAL climb.
Again think too much blame pointing at the pilots..(all dead men who can not defend their corner)