Is there any case law or case law in which a defence counsel has been found to have made out deficiencies in the credibility assessment?

In our view, the relevant inquiry is whether the listed deficiencies, even if made out (upon which we express no opinion), in the course of this difficult but imperfect trial, impugn the credibility assessment. The record as a whole suggests otherwise. By way of example, the mental health evidence, even if successfully objected to, would not have altered the credibility findings of the trial judge who made no reference to that evidence. The alleged improper use of notes by the witnesses to refresh their memory, even if objected to, would likely have been permitted. As to the suggestion of collusion among the witnesses, it would have been apparent to the trial judge that a number of the witnesses, particularly those living in the same household, would have compared notes which in no way would have detracted from the clear and unequivocal acceptance of their testimony by the trial judge. Failure on the part of defence counsel at trial to comply with Browne v. Dunn (1893), 6 R 67 (HL) is also of no moment. The trial judge said expressly that any such failure had no effect on the outcome. (AR 125/4-12)