Out of interest, was that in reply to the quoted paragraph, or was that in reply to my original article that this quote was taken from?

I'm guessing the former, since you seem to be responding just to that paragraph rather than the main thrust of the article. If you're interested, the original is here, and an architect on the relevant team replied here, and I replied to that here.

For what it's worth, I don't think the reason for the misconception had anything to do with the competence of the presentations, which is what you appear to be implying. I believe it was a conscious decision on Microsoft's part to push the technical aspects for the rather obvious reason that the audience at the Professional Developers Conference was mostly made up of Professional Developers...

So the point of the article wasn't really to have a go at the presentation, but to call out a different aspect of the technology. I think they put across precisely the points they meant to put across on Avalon at the PDC.