On the A330/340
The A/T only retards the thrust when doing a autoland.
If you're manually flying the A/T is in SPEED mode as it would be with the AP in, but as you flare the A/T will add thrust to maintain speed, that's why the retard feature is there.
With non moving thrust levers in a high workload you may be a bit slow retarding the thrust, also in turbulent conditions you may actually be happy to accept the increasing thrust during the flare to help arrest the descent, you will get the "retard retard" even though you actually want more thrust.
I always used manual thrust as I liked being in the loop.
SMOC