Rudderrat
Hi OK465, DW, henra,
Unless the aircraft was trimmed exactly to balance any asymmetric thrust (due TL moved in response to thrust lock), it would tend to roll one way and continue to roll, unless counteracted by pilot or Auto Pilot input.
Since it was in Alternate Law, there was no AP or FBW roll input - only pilot input.
At what attitude do you think it would stop rolling if left by itself?
With an aircraft stalled the roll would lead to yaw in the direction of the roll. As the 330 is swept wing the wing on the downside would then be more directly into what airflow there was and generate slightly more lift and the aircraft would nod up and start rolling back the other way to repeat the yaw and roll on the other side. As I believe Dozy has said this is relatively standard swept wing behavior. Like a long period dutch-roll
However, into this action PF was putting in as much aileron as he could, often apparently full SS. The result of this would be to make the
low wing AOA higher so less lift so a tendency for the aircraft to apparently do the opposite of what was wanted until the wing sweep effect was larger than the aileron AOA effect.
Perhaps someone with spare time could check - but if the total time with the SS held
to the left is larger than to the right then that could explain the overall
right turn in the descent track as the right wing was being held deeper in the stall by aileron AOA.
Speculation now - but for a pilot sitting in the right hand seat, just pulling the stick directly toward the pilot would be a Nose Up - Left Roll input. This would maintain the stall and result in a track that turned to the right.