Joe
my first impression is that the 7000 fpm climb is not necessarily pilot induced but instead it is a 7000 fpm updraft.
Unlikely.
A big cell might have an updraft of 5,000 ft per min, but this aircraft was doing 11,000 ft per min. Now that is the max updraft from the absolute largest of supercells. Were conditions that bad? And if so, why was a cell of this size not avoided? And the engines are not going to contribute much to the climb, as I doubt if you could get 1,000 ft per min from the engines at that altitude, without a zoom climb.
The more likely scenario is a smaller updraft upset, combined with and exacerbated by poor handling of the upset, pitching the aircraft up. We shall see.
As an aside, I have not flown the 'bus. So to the 'bus drivers out there, what would it do, if you deliberately pulled back to 40 degs pitch up, to try and stall it? Would it foresee and cope with the aggressive attitude, or would it go out of envelope and stall?