When you lose the 2nd RA, the F/Ctl will switch to Direct and AP trips as long as the LG is down....
the plane is made that way because the Flare mode (100 ft on A330) is no longer available in dual RA fault and Airbus has to select a point during approach where the autotrim must be stopped to facilitate the landing and make it natural and easy and that point was L/G down.....
the Direct Law in such a failure (dual RA fault) is not like any other Direct law. It is close to being Normal Law w/o autotrim....
sorry if my wording is not understandable as English is not my native language....