Forgive please, if this is already addressed...
During the descent - in a nearly level attitude - the aircraft turned either 90 to the right, or 270 to the left. Now then -
If the crew actually felt they were overspeed, and noted the fact they were changing direction, did they not feel the centrifugal force that would be created by that change in velocity vector?
With benefit of hindsight, this would seem to be a crude but effective means of differentiating between overspeed vs underspeed, when Pitot instruments are unreliable. Turning at anything approaching a standard rate, at or above cruise Mach, would glue one to his seat.
