According to what I was told the theory was that lift was more due to the speed of the air over the wing rather than the speed through the air thus the design. This extrapolated that change in thrust changed the lift due to the design thus no need for ailerons !! I asked whether the thrust was tied in to the controls for this purpose but no, apparently done with the thrust levers !!
One thing that I thought is that loss of an engine in this situation would not be a good thing !