There are several causes for this problem, pilot error, effects of high-speed flight, incorrectly connected controls and various coupling forces on the aircraft.
In unusual attitudes it is not uncommon for the pilot to become disoriented and make incorrect control movements to regain level flight.
It is a recurring problem after maintenance on aircraft, notably home built designs that are being flown for the first time after some minor work.
It is not entirely uncommon on commercial aircraft, and has been the cause of several accidents including the crash of the Short Crusader before the 1927 Schneider Trophy and the 1947 death of Avro designer Roy Chadwick.
If this yaw was violent enough, the additional speed on the lower wing as it was driven forward would make it generate more lift, and reverse the direction of the roll.
[5] The Boeing B-47 was speed limited at low altitudes because the large, flexible wings would cancel out the effect of the control surfaces under some circumstances.