Trevor Thom Volume 1 (my copy is the 2005 edition) on p 37 presents two bullet points under the heading of Yaw causes Roll summarised below:
- the outer wing moving faster than the inner wing, and
- the stuff about dihedral
They are presented in that order. It also goes on to say the inner wing will be somewhat shielded from the airflow by the fuselage and produce less lift.
Both bullets seem entirely plausible to me as a non-expert in aerodynamics. But my inference, because of the order in which they were presented in the book, was that the first bullet was the more significant one, and that (first bullet) was how it was explained to me when I was briefed on effects of controls - no mention of bullet 2.
I note that the OP has not reappeared - probably even more confused now!