The elevators were max NU and held the attitude at +16°. I wouldn't get too excited about the stalled tailplane, as the drag caused by the vortex was assisting its lift, and airflow over the aerofoil, i.e. the THS and/or elevators, need only act as a lever to force the NU or ND as required.
Interesting comment. When down elevator is applied what happens to the "vortex" drag that is "assisting it's lift"? Seems to me it would reduce.