BOAC - we don't know the details of the SS movement so it isn't possible to correlate such movement with rate of climb. The aircraft would have had a nominal pitch attitude of around 2.8deg roughly - SS movement aft of 3 - 4cm (previously said 2 - 3cm), as measured at the top of the stick would produce an enormous but clearly brief rate of climb of the kind we see here - it would be the equivalent I suspect, of about a six-inch rearward movement of the control column on the B737, just to try to equate a sense of the large changes involved in pitch and climb.
"Two-hundred tonnes" I believe is immaterial here as the wings produce commensurate lift for the design. It is a matter of mass, momentum and available energy (far more than 200T worth) from the wings at the initial CAS, which, given the eventual pitch attitude of 15deg clearly would be quickly unsustainable but in the short term, achievable. The BEA Update states that the VSI reduced to 700fpm and it is easy to understand/imagine the ballistic trajectory which resulted prior to the start of the descent.
Aside from my original thoughts of responding to the UAS drill instead of "doing nothing" while getting out the QRH for pitch-and-power settings, this almost looks like this was a reversion to original training where the approach to the stall is taught in transition or initial courses at lower altitudes in which the goals have traditionally been minimum loss of altitude, (much discussed in earlier threads) and "powering out of the stall" using TOGA thrust. The initial pitch attitude just may be some over-controlling which resulted in checking the stick forward a bit before responding again to the stall warning with back-stick, (driving the THS up, as we see). As I mentioned a number of times before, once the aircraft departed level flight, the "knowns and cues" for stable, level flight were gone and situational awareness, (what pitch? what power?) became problematic. The simulator exercise required a lot of nose down and I don't recall seeing what the THS actually did during the exercise and didn't look at the THS indiction. The descent rate was 7500fpm and the stick had to be held full forward. This was a stall from a pitch-up and the PFD looked like this in the recovery:
