Uh, yeah, a technicality it is. And I would argue that the two have become to mean mostly the same thing. Because if you look at the second link I posted, the guy calls them "knickers" throughout, and yet he mentions:

<i>"We decided not to rebuild the ankle draw string because my calves are big enough that it would not get used."</i>

Like you said, whatever. Tomato vs. Tomahto... although I'm not about to start referring to my trousers as "capris" or "manpris".