vilas
The difference in the two failures seems to be caused by ailerons.
Partly true. The other differences are A/THR OFF and No Slats and with Hyd B & G SYS Lo
PR.
Any induced roll caused by half an elevator and having only wing spoilers should be easily controllable with some rudder input.
I think the big difference is caused by going from a clean wing to F2 below 200 Kts. There is a big shift aft of C of L causing a nose down pitch couple (due to Flaps 15 but no Slats at 22). If it exceeded the rate at which ALT LAW in pitch (with only half an elevator) could control the pitch change, then the nose would lower. If A/THR was on, any speed increase would cause a thrust reduction and a further nose down couple making control more difficult.
I think Airbus discovered the problem was better controlled using manual thrust & Direct Law feed back to the pilots to appreciate the trim change necessary.