> the CIA proclaims that FLT800 fell from the apex of a
> dramatic climb (and thus from rest)
Even if it is no longer climbing, that does not mean at rest. It has considerable forward momentum: that was, and is, what generates the lift to get to that apex.
One needs to know what the flight recorder says about power during the descent. If the pilots were not in control it will have made a potentially full throttle decent. If they were in control they are going to need to power the plane down to get leverage of their control surfaces. Either way there is no way to answer this from Galileo alone.