What is the test for a primary carer who fled with her children from an abusive home in Italy to escape prosecution?

In DT v. LBT, [2010] EWHC 3177 (Fam), an English mother fled with the children from an abusive home in Italy to Britain, where the children had been born. The court found the level of abuse in the home rose to the level required by article 13 (b). In par. 23 of the case, the court listed a number of principles it adopted. They included: (8) The court requires clear and compelling evidence of a grave risk of harm or of a situation that the child should not be expected to tolerate. It is a high threshold. (9) The court will look narrowly at an assertion by an abducting parent that the child's situation will be intolerable as a result of the parent's refusal to return with the child. However, this is not to be elevated into an absolute rule. Primary carers who have fled from abuse and maltreatment should not be expected to return to it if this will have a seriously detrimental effect on the children. (10) In a Brussels HR case, the court cannot refuse to return a child on the basis of grave risk of harm if it is demonstrated that the authorities in that state have made adequate and effective arrangements to protect the child after return. (11) A situation that might otherwise be intolerable can be alleviated by the provision of appropriate undertakings. (12) Where the defence of intolerability is made out, it is difficult to envisage an order for return being made.