Here's another way to think about it.

Consider straight and level flight, including gravity, for an aircraft
with dihedral. Consider the "lift" vectors of each of the wings. (They
are not pointed up, they are actually pointed slightly inward due to the
dihedral).

Now, instead of rolling the airplane, swing the entire earth arround so
that the earth (and its gravity) is coming from the right somewhere.
The lift vectors on the wings do NOT change! NO rolling moment is
produced...

until...

....the airplane starts getting dragged to the right by the newly
misplaced earth. Of course, it's being dragged sideways against the
air. ONLY THEN will the AOA change for the wings, directly due to the
sideways slipping of the airplane.

Jose
--
Nothing takes longer than a shortcut.
for Email, make the obvious change in the address.