I believe it's happened, more than once. I had the same thought and figured, depending on which stage one side was jammed on, if opposite aileron and/or rudder were not enough to counter the extra lift on the jammed side, there wouldn't be much else you could do. You could perhaps counter the extra drag (and subsequent yaw) by opening the opposite door (and holding it open an amount with the third hand) but, you might end up with too much drag. All a bit too much for my O level brain really and I hope I never have to find out if it would work...................