When is a duck not a duck?
"...applies to all contractors and freelancers who do not fall under HMRC's definition of being self-employed."
The biggest problem I have found is that HMRC are deliberately vague about the rules. There seems to be no cast-in-stone checklist you can go to to definitively check IR35 status.
Of course, this is deliberate - HMRC like things vague so that they can make the rules up as they go along. Which they do on a very regular basis, and not just with regard to IR35