Sorry for starting the argument but there are certainly aircraft in which a combination of aft trim and underslung engines at high power can cause uncontrollable pitch up at slow speeds, such that stall recovery becomes difficult. Some models of 737, for instance, hence the Boeing and Airbus guidance. All pilots of under-wing engined aircraft should be aware of these effects. If you have run out of other options, it's something to try, much like reducing thrust on the good engine if you're below Vmca after a failure.
If load shift happened as a result (apart from not being locked down) of pitch up, and was not controllable, how did a stalled aircraft manage to pitch over? Wouldn't a massively aft cofg force to it descend nose up? It was far too slow for control surfaces to overcome that?
Relative to the horizon, it does pitch down. Because the rate of descent was of the same magnitude as the forward speed, the
angle of attack of the wing was very high, likely 40-50degs. The aircraft, relative to the airflow, was very much tail low still. To unstall the wings would require a further pitch down of c.30degs or more from what we see in the final moments.