… The question arises, however, whether the ‘common continuing intention’ is to be assessed by reference to the parties’ subjective intentions or by reference to what an objective observer would have thought the parties’ intentions to be. In 2009, obiter dicta of Lord Hoffmann in Chartbrook Ltd v Persimmon Homes Ltd suggested the objective approach to be the correct one. That conclusion proved to be controversial. It left the law of rectification ‘marred by uncertainty and complexity’, with much ‘left in the air … within [its] jurisprudence’. In FSHC Group Holdings Ltd v GLAS Trust Corp Ltd, following a comprehensive analysis of the historical development of rectification and the relevant authorities, the Court of Appeal has declined to follow Lord Hoffmann’s objective approach, instead adopting a subjective approach to the question of common continuing intention to the facts of that case. The conclusion in FSHC is consistent with orthodoxy prior to Chartbrook, sound in terms of policy and principle, and must be correct …
Adam Shaw-Mellors, ‘Rectifying rectification: the subjective approach to rectification for common mistake’  Journal of Business Law (5) 368-381.