“The references in the [Statement of Case] to an overall scheme to defraud the revenue involving an orchestrated and contrived series of transactions are, I accept, details as to relevant circumstances surrounding [E Buyer’s] transactions, which HMRC may relevantly allege in order to establish, if they can, the context in which [E Buyer’s] transactions took place. Establishing this context will be relevant as it will assist the tribunal in determining what [E Buyer] knew or ought to have known…”