Originally Posted by
Centaurus
Instead of using immediate strong elevator force coupled with careful forward blips to the stab trim to contain the pitch up, the pilot uses the stabiliser trim switch in a continuous motion and keeps his thumb on the switch waiting for a reaction. 12 seconds is a long time to wait for the nose to lower and by then it goes nose down rapidly and no hope of recovery at low altitude on instruments.
From all we know this description seems to hit the nail on the head.
Unfortunately the pure readings from CVR/FDR will not be able to finally and undoubtedly confirm this 'why'. It should at least hopefully be able to distinguish if it was an uncommanded trim runaway or a commanded action. If it was the latter, your description is probably as good as it gets.