The author actually discusses this a bit towards the end. Far from it. As early as the first subsection, "A Less Than 0% Chance", Scott writes: "Now, what hap

The author actually discusses this a bit towards the end. Far from it. As early as the first subsection, "A Less Than 0% Chance", Scott writes: "Now, what happens if you try to come up with a theory that's like probability theory, but based on the 2-norm instead of the 1-norm? I'm going to try to convince you that quantum mechanics is what inevitably results." So discussing that distinction is the entire point of the lecture, and not some minor point "discussed a bit towards the end".