“11. A first instance judge's assessment of, or evaluations based upon, expert evidence adduced at trial must be approached by an appellate court with similar caution. Whilst it has been said that a reconsideration of an expert's opinion may be slightly easier than a finding of fact, because the underlying report will be in writing (see Thomson v Christie Manson & Woods Ltd[2005] EWCA Civ 555 ; [2005] PNLR 38), the same case also provides a salutary warning that, since the evaluation of expert evidence is likely to be bound up with a wider evaluation of matters of fact, an appellate court will still be very slow to intervene. At para 141 of his judgement in Thomson's case, May LJ said: “But, even accepting that individual points such as these are amenable to judicial appellate evaluation whatever the expert opinion, no appellate court should cherry pick a few such points so as to disagree with a composite first instance decision which, in the nature of a jig-saw, depended on the interlocking of a very large number of individual pieces, each the subject of oral expert evidence which the appellate court has not heard.”” “But, even accepting that individual points such as these are amenable to judicial appellate evaluation whatever the expert opinion, no appellate court should cherry pick a few such points so as to disagree with a composite first instance decision which, in the nature of a jig-saw, depended on the interlocking of a very large number of individual pieces, each the subject of oral expert evidence which the appellate court has not heard.””