Lyman,
At the first time, the VS was 15000. In about a minute, they fell only 10000.
Don't know if you took Physics in High School or not, but there was a lesson some schools offered: If you drop a feather in a vacuum tube, it reaches the bottom of the tube at the same time as a marble (a tie). Add some atmosphere (air), the marble wins the race. Add even more atmosphere, the marble wins by a much bigger margin.
Now think about two feathers attached to a hay stalk falling flat in ever increasing atmosphere (more air). It falls ever slower during descent, as the air gets thicker creating more resistance, proving several important aspects of physics. Same is true of an A-330 falling nearly flat from 38,000 feet to 20,082 feet to 10,092 feet and on down.
If VS reduced at a constant rate, would it not be ~5000 fpm at 10000 feet?
It is not and that is why it is not ~5000 fpm at 10,000 feet.
That means the VS reduced substantially. Very substantially. What happened that was "Impossible" that drastically reduced their Vertical descent? Greatly increased forward velocity?
Ever denser air is a known fact.
Would that have elicited some conversation in the cockpit?
Is this part of the imagined "missing CVR record?"
"The absence of FULL DISCLOSURE, is a species of FRAUD"
Only if it is imagined but portrayed as being the whole truth and nothing but the truth.