Duty of care
The Claimants' central argument (which had not been advanced at first instance) was that this was a 'prospectus-type' case. The Claimants contended that Mr Thornhill KC, by consenting to the inclusion of his advice in the Information Memorandums in the knowledge these would be received by third parties, induced the Claimants to invest in the Scheme. Accordingly, the Claimants' argument proceeded on the basis that Mr Thornhill KC owed a duty of care to the investors that was analogous to the statutory duty owed by those responsible for the preparation of a prospectus to those subscribing to the issue of shares. The Court rejected this argument as 'untenable' on the basis that the Scheme constituted an unregulated investment and that Parliament had expressly limited the statutory regime's application to regulated investments.
Applying the principles set out in the Supreme Court's judgment in NRAM v Steel, the Court also held that it was neither objectively reasonable for the investors to rely on Mr Thornhill KC's advice as if it was advice given to them, nor foreseeable that they would do so. The Claimants and the Scheme's promoter were 'commercial counterparties' on opposite sides of an arm's length transaction and it was therefore 'presumptively inappropriate' for the investors to rely on Mr Thornhill KC's advice. The Court emphasised that the Scheme had only been marketed to wealthy and sophisticated prospective investors who were able to access independent tax advice; the Information Memorandums stated plainly that prospective investors should consult their own tax advisers, and all investors were required to warrant that they had done so. The Court further held, in agreement with Zacaroli J at first instance, that the warranties were neither 'no reliance clauses', nor a disclaimer of responsibility, and that UCTA 1977 did not render these warranties unenforceable.
Breach and causation
The Court of Appeal then addressed, obiter, the question of whether Mr Thornhill KC's advice was negligent so as to breach a hypothetical duty of care owed to the investors. The Court departed from Zacaroli J's earlier conclusion and criticised the unequivocal nature of Mr Thornhill KC's advice as falling below the standard of a 'reasonably competent tax silk'.
However, ultimately, the Claimants' success on breach provided little consolation in circumstances in which their arguments on causation were rejected by the Court of Appeal. Contrary to the Claimants' submissions, Mr Thornhill KC was not required to warn investors of a significant risk that HMRC would challenge the Scheme successfully. Non-negligent advice would have involved Mr Thornhill KC giving a far gentler warning of the risks of a successful challenge by HMRC, such that the Claimants 'came nowhere close' to establishing that they would have acted differently (and avoided the loss) in the counterfactual.