For non A/Bus people. Imagine doing an approach in CWS (not that you would) then as you start the flare the CWS drops out and the input (back stick) you have just made doubles or even trebles, that may give you an idea of why a double rad alt fail at a late stage can give control problems. The a/bus handles well in direct law, but the controls are very powfull.
(CWS=Control Wheel Steering)