I am glad you posted this. Not because it revealed new information, but...
Owners make many assumptions about the DCT ; yea, it's a fairly new concept.
Although the owner's manual and some WWWeb articles describe how it works, there
are some areas that do need clarification.
Most of the times we settle on one method of riding the DCT, because it works
and s/he has done it that way since they started. No one took a "DCT101" class.
(I think Honda should develop one and the MSF should adopt it, sooner than later)
The point I am trying to make is that another option to override DCT downshifts is
to give the throttle a bit of twist or a bit more to shift down 1 or 2 gears.
Of course at any given situation, you would choose the appropriate override method.
As for me, I seldom use MT mode nor get into a situation where I would use the paddle shifter to downshift.
It's more fun to leave it in D or S and just twist and go!