I looked it up in the digital copy I have. Picking all that apart would be quite a task, but I wanted to see what the context of that statement was. I read on passed page 16 and found this paragraph:

Still the severer antiquary may think, that, by thus intermingling fiction with truth, I am polluting the well of history with modern inventions, and impressing upon the rising generation false ideas of the age which I describe. I cannot but in some sense admit the force of this reasoning, which I yet hope to traverse by the following considerations.

And he goes on, and on, and on...

I just don't trust Scott as a source of historical information, however, he is an interesting source of historical mythologies relating to Scotland. I know very little more than that, but if you can produce other sources that are primary, it would be nice.