The Supreme Court has today unanimously allowed the mother's appeal in S (a Child). You can read a press summary of the judgment here, and the full judgment here.
To recap (from the Supreme Court case summary), the issue was the approach that the court ought to take to summary applications under the Hague Convention when Article 13(b) is engaged; and the application in this regard of the guidance given in Re E  UKSC 27.The facts were:
The Appellant mother and the Respondent father lived in Australia with their young son. The mother asserts that the father was a drug user, became violent, abusive and threatening towards her and that there were severe financial problems. In February 2011 she took the child to the UK, from where she originated, without the Respondent’s consent or knowledge. The father sought an order for the child’s return to Australia under the Hague Convention. The mother asserted that a return to Australia would cause practical problems, and would cause psychological upset to her, to the extent that the child would be placed in an intolerable situation. The High Court refused to order the child's return to Australia, finding that the exception provided for by Article 13(b) of the Convention was engaged and satisfied. The Court of Appeal reversed that decision and ordered the child's return. The case concerns the approach that ought to be taken to the assessment of the evidence in such situations. The High Court and the Court of Appeal refer to guidance on the Article 13(b) exception given by the Supreme Court in Re E (Children) (Abduction: Custody Appeal)  UKSC 27;  1 A.C. 144, including as to the potential relevance of protective measures. The main questions before the Supreme Court are (i) as to whether, and if so in what circumstances, the Article 13(b) exception can be established on the basis of the subjective perceptions of the abducting parent; and (ii) the circumstances in which an appellate court is entitled to interfere with an assessment made by the judge at first instance.The Supreme Court has unanimously reversed the decision of the Court of Appeal, and restored the order of Mr Justice Charles in the High Court. Delivering the judgment, Lord Wilson concluded:
"As we have explained, the Court of Appeal failed to appreciate that the mother’s fears about the father’s likely conduct rested on much more than disputed allegations. Equally it paid scant regard to the unusually powerful nature of the medical evidence about the mother ... Overarchingly, however, it failed to recognise that the judgement about the level of risk which was required to be made by article 13(b) was one which fell to be made by Charles J and that it should not overturn his judgement unless, whether by reference to the law or to the evidence, it had not been open to him to make it. Charles J was right to give central consideration to the interim protective measures offered by the father. But his judgement was that, in the light of the established history between the parents and of the mother’s acute psychological frailty for which three professionals vouched, they did not obviate the grave risk to W. It must have been a difficult decision to reach but, in the view of this court, it was open to him to make that judgement; and so it was not open to the Court of Appeal to substitute its contrary view."The judgment has been welcomed by the child abduction charity reunite (which was permitted to intervene in the proceedings), for "reaffirming the clear principles stated in the helpful and important previous decision of the Court in In re E (Children) (Abduction: Custody Appeal)."