Alf,
You really feel passionately about this, so I'm hesitant to draw this out any further, but since I took the time to read your linked blog post I'm going to give you my thoughts anyway.
It seems to me the reason, if any, that RF focusing may be more accurate than live view on the M 240 as indicated in the blog you linked to is only because magnified live view on the M 240 is only in the center area and the area of magnification can not be moved around like on many other cameras with an EVF. So rather than see this as a shortfall of focusing with EVF's in general, I see this as merely a knock on Leica's implementation of live view on the M 240. If you could place the area of magnified live view on the spot in your image where you wanted the center of focus, I have no doubt that magnified live view would be as accurate or more accurate than the range finder mechanism.