This ties in with another current question about why we do not have larger elevators on airliners, and highlights the potential of accelerated stalls.
Aircraft need proper air flow over the wing to produce adequate lift. This is a function not only of speed, but also of angle of attack. The lift to angle of attack chart illustrates this.
One of the key functions of a properly designed horizontal stabilizer is to push the nose down when the plane sinks. The design parameter is to have this have adequate area on the H stab to lower the nose as it sinks before it stalls. The pilot adds power to resume level flight.
The other critical factor is center of gravity. A forward set CG again pulls the nose down as the plane slows. Forward set CG acts as a counter balance to elevator trim to stabilize air speed to a desired range: slower - nose down, faster - nose up.
It is the position of the elevator that creates the AOA to stall the aircraft. If the elevator is stronger than the torques created by Hstab while sinking and forward CG, the plane cannot sufficiently reduce AOA.
Sadly, even with power applied, the stall can not be broken until the elevator is released. In the report of this incident, although pitch did not exceed 15 degrees relative to the horizon, AOA exceeded 35 degrees even with throttle at TO/GA, and the aircraft was falling at over 10,000 feet per minute. Weight and balance were within limits.