I don't think it's wrong -- it just doesn't explain it very well. If you are descending in SPD mode on the A/T (say SPD||V/S) and you manually override the throttles by pulling the power back, the throttles will just go back to maintaining the select speed when you let go of them.
But if you do that while in THR||FLCH SPD, the A/T goes to HOLD||FLCH SPD and the power will not move back when you let go of the throttles.