Lyman;
I've expanded some of the FDR traces and in the case of the Pitch attitude one have added the Elevator and Stabilizer positions (inverted) for easy comparison. Immediately above is the Normal acceleration trace.
My summation is that the aircraft responded very well to the PF's inputs (as represented by the Elevator and Stabilizer positions) after the A/P hand-off, but just prior to, the turbulence had created a pitching moment that didn't correlate with the vertical speed. Hence the A/P disconnect.
The UAS was a secondary.
EDIT: Patently not true, as the RTLU was locked at 02:10:04.5 in response to the ADRs rejecting the two speeds recorded, or more precisely the Mach value of one of them.
The two airspeeds recorded were still valid at this time; however, a false value point is present in the recording of the Mach. The low sampling frequency makes it impossible to determine the duration of the disturbance in the measured values; however, it is likely that it corresponds to when monitoring was triggered. (BEA Interim Report No.3)
The UAS was the primary reason for A/P disconnect.
EDIT #2: An interactive version of this graphic with vertical/horizontal Cross Hairs and additional time marks and scale is available
here. You can also expand your browser page using Ctrl + and return to normal with Ctrl 0.