Hi DozyWannabe,
On reflection, I think the side slip trace has some error - I can't see why it would peak at -10 so regularly. So ignoring that:
If you look at Aileron Displacement, before AP disconnect the pattern is symmetrical and seems to include all 4 ailerons.
After AP disconnect, the trace only shows the inner ailerons were active. The deflections show far more LH Inner Aileron around> -10 ( = Left inner UP). It indicates that the aircraft had a continuous desire to roll right, counteracted by a more frequent roll Left command.
The tendency to roll could have been solved with rudder trim.