I couldn't help but notice that there were two cases both named In the matter of B (Children) reported on Family Law Week this week. The two cases are not related, but both involve expert witnesses and both are of interest in their differing ways.
The first case chronologically was B (Children)  EWCA Civ 1034. In this case the mother was applying for permission to relocate to her native Germany, with the two children. Her application was refused by Her Honour Judge Hallon in the Bromley County Court and she sought leave to appeal. Her counsel argued that the judge had given too much weight to the evidence of an expert who had prepared a report much earlier in the proceedings. According to counsel, that report had been "anodyne", but when she gave evidence at the hearing she had been trenchantly against the mother's application, despite having had nothing to do with the case for some considerable time: "Effectively [counsel] says that he was ambushed". In the Court of Appeal Lord Justice Thorpe had some sympathy for counsel, "but the problem for [him] is that he raised no objection at the crucial moment with the witness there before the court answering questions in her live evidence". The judge was therefore entitled to place reliance on the expert's evidence. Accordingly, whilst leave to appeal was granted, the appeal itself was refused.
The second case was B (Children)  EWCA Civ 1037. In this case the applicant was seeking leave to appeal against a finding of fact in care proceedings that he had sexually abused children. The finding was based upon evidence of children witnesses with no independent corroborating evidence, but an expert had given the opinion that the evidence of one of the children was "probably true", second from the top of his own seven-point scale for evaluating such evidence. It was argued that the judge should not have accepted this as crossing the balance of probabilities threshold of proof, as the expert had not considered the evidence to meet the top of his scale: "very probably true". This was not accepted by Lord Justice Hughes in the Court of Appeal, who found that: "For my part, one would have thought that “probably true” seems incapable of meaning anything less than that the allegation is proved on the balance of probabilities. But even if there is room for debate about what [the expert] meant, it is absolutely clear that the judge applied the correct test". The application for leave to appeal was therefore refused.