Composite Companies and IR35

To summarise, in his question Paul Reynolds asks which is safer with regards to IR35, working through a composite company or having your own limited company. Specifically he mentions fellow contractors who "worked through a composite company receiving a minimum wage and the balance in dividends and expenses" in cases where he believes IR35 applies. Barry Roback replies noting these schemes are fraudulent under the new Money Laundering Act 2004.

I read with interest that UKTECH has teamed up with Consulting Overseas to offer "alternative tax planning solutions to freelancers".

I'd already heard good things about Consulting Overseas through colleagues and was interested to know more and so contacted them. They were very friendly and explained to me that should I join I would be paid a small salary and would receive the remainder of my income in expenses and dividends. They also explained the benefits of their IR35 insurance with QDOS and how if I was married my wife could be paid dividends. No IR35 or S660 worries, no paperwork and a high income. I was/am impressed.

Referring back to Barry's comments it would seem that it's very important IR35 doesn't apply before joining. However, my understanding is that all one needs to do to join Consulting Overseas is to have the correct contract wording, which I think is just about everyone in IT nowadays, irrespective of their IR35 position. Unless I have misunderstood I suspect that many people who are actually caught by IR35 can join Consulting Overseas if they wish. In fact if they believe they are caught it makes sense to join as they are then protected against an investigation and potential losses by the QDOS insurance.

I understand that tax experts have confirmed that Consulting Overseas operate within the law and UKTECH has looked in detail at the scheme and endorse it. To the layman it's difficult to see the difference between them and what Paul Reynolds is talking about and so I am confused by Barry Roback's comments.

So my questions are: What distinguishes the legal tax planning solution from the "fraudulent, money launderer"? Is it simply the fact that the correct contract wording is in place? If so, is it not possible the people Paul Reynolds talks about are in fact within the law if they have the correct contract wording?