Trim
Re the difference in aileron position (report page 28); is there anything odd about a difference of about 2 deg between them with the autopilot engaged and reasonable tracking when disengaged? Larger differences during the descent might be attributed to excessive air loads.
Does the autopilot trim the aileron, or are the crew expected to trim out any hand-wheel offset?
The line of thought is that there might have been some residual aileron trim which could add some confusion to a disorientating situation; crews normally expect zero roll rate to equate with zero force.