The Court of Appeal handed down a judgment on the 5th April 2022 which gave this guidance:-
i) An appeal court should not interfere with the trial judge’s conclusions on primary facts unless it is satisfied that he was plainly wrong.
ii) The adverb “plainly” does not refer to the degree of confidence felt by the appeal court that it would not have reached the same conclusion as the trial judge. It does not matter, with whatever degree of certainty, that the appeal court considers that it would have reached a different conclusion. What matters is whether the decision under appeal is one that no reasonable judge could have reached.
iii) An appeal court is bound, unless there is compelling reason to the contrary, to assume that the trial judge has taken the whole of the evidence into his consideration. The mere fact that a judge does not mention a specific piece of evidence does not mean that he overlooked it.
iv) The validity of the findings of fact made by a trial judge is not aptly tested by considering whether the judgment presents a balanced account of the evidence. The trial judge must of course consider all the material evidence (although it need not all be discussed in his judgment). The weight which he gives to it is however pre-eminently a matter for him.
v) An appeal court can therefore set aside a judgment on the basis that the judge failed to give the evidence a balanced consideration only if the judge’s conclusion was rationally insupportable.
vi) Reasons for judgment will always be capable of having been better expressed. An appeal court should not subject a judgment to narrow textual analysis. Nor should it be picked over or construed as though it was a piece of legislation or a contract.
An appellant’s case will fail if:-
i) It seeks to retry the case afresh.
ii) It rests on a selection of evidence rather than the whole of the evidence that the judge heard (what I have elsewhere called “island hopping”).
iii) It seeks to persuade an appeal court to form its own evaluation of the reliability of witness evidence when that is the quintessential function of the trial judge who has seen and heard the witnesses.
iv) It seeks to persuade the appeal court to reattribute weight to the different strands of evidence.
v) It concentrates on particular verbal expressions that the judge used rather than engaging with the substance of his findings.