I posted a while ago the argument that they may not have climbed at all between waypoint change and impact - remember that just two points gave an indication of climb: last altitude update and point of impact; the encoding altimeter has a very coarse resolution and, all factors put in, from the highest level to the point of impact was easily within the height that the airmass would have carried them up the slope.
I have it that they were coasting in, letting their speed wash off a bit, and not intentionally climbing.
That the final control inputs were the result of a last moment realisation of their proximity to the ground is evidenced by the state of the engines - while (as Chinook 240 reminds us) actuators had responded meaningfully to the control inputs, the engines had not time to increase power - let me repeat briefly my previous detailed explanation of this because it offers such an important clue as to what happened:
the engine management system tries to hold rotor RPM to 100% +/- 0.5%;
the engines were found matched, something which may take a moment for either the FADEC or a pilot (with his beep trim) to achieve - this indicates that a steady state had preceded any last moment thrust demand;
the power level was intermediate, consistent with slowing down as to have maintained their cruising speed would have required a higher level;
as one slows down (as in coasting/letting the speed wash off whilst maintaining altitude and aircraft attitude) from a high speed the drag on the rotors reduces and there would be a tendency for them to speed up but the engine management system will reduce the fuel to keep the rotors within the +/- 0.5% - hence in this scenario one would expect the rotors to have been at 100.5% which what they were found to have been at at impact;
as already mentioned, controls had been moved which had meaningful results in the various servos/actuators consistent with a manoeuvre other than carrying on straight and level and it would have been consistent with a last moment evasive manoeuvre to have pulled up on the collective/thrust lever and this was very much the case (really was pulled up wasn't it) BUT
this would have been demanding full/emergency power as Sqn Ldr Burke so rightly commented saying that it would have been impossible to have maintained rotor RPM with that demand - I SAY THAT THE ROTORS HAD NOT HAD TIME TO SLOW DOWN SO LITTLE WAS THE TIME BETWEEN THIS DEMAND AND IMPACT.
So steady state intermediate power to an extreme demand which did not have time to manifest itself - they were surprised at their proximity to the ground.