Genghis the Engineer - thank you for your very informative reply.
It would seem most likely that a flap might detach on the approach and (possibly) towards the late stages when full flap is taken and the load is at its highest.
Is it your general view that were a flap to let go in this configuration (but lets say with rather more height to work with than would actually be the case on late final) the average GA type would have enough authority in the ailerons to prevent the aircraft turning over. I appreciate an early retraction of the flap would be vital but I suspect the loss of a flap would come as such a surprise that the first reaction would be to compensate with aileron whilst working out what had failed.