To the best of my knowledge there is no way this can happen (1 side of his flaps retract while the other side stayed stuck down...) if one side became disconnected to the other i.e. mechanical failure, air flow would return the flap to the negative position. If you fly a manual flap Jab and don’t put the handle in the detent position positively the flaps will retract all by them selves. I can think of no scenario where one flap could stay deployed.
Perhaps you could explain how?