M (Children), Re

In a care fact-finding case involving disputed medical causation, the court must allow for the possibility that an injury has an unknown cause. That possibility does not alter the burden or standard of proof. It does mean that non-accidental injury cannot safely be inferred merely because no understood natural mechanism has been identified.

Where expert evidence establishes that an infant’s presentation is medically inexplicable, rejection of the carers’ accounts does not alone justify a finding of non-accidental injury. The judge must explain the safe evidential and inferential route by which the finding is reached on the totality of the evidence. A failure to do so on the central issue vitiates the fact-finding decision.

During care proceedings concerning two children, the county court conducted a seven-day fact-finding hearing into fractures suffered by M, then aged five months. M had rib fractures occurring on at least two occasions and extensive bilateral skull fractures.

The medical experts agreed that the skull fractures were exceptionally severe but were unaccompanied by the brain injury, scalp swelling, pain and clinical disturbance ordinarily expected. They could not explain that presentation. The judge found the injuries non-accidental, rejected the parents’ accounts, and retained both parents in the pool of possible perpetrators.

The father appealed with the mother’s support. The central issue was whether the judge had adequately explained her conclusion that the injuries were non-accidental despite the medically unexplained nature of the skull fractures.

Appeal allowed unanimously. Munby LJ gave the reasons, with which Kitchin LJ and Sir Stephen Sedley agreed. The fact-finding conclusions could not stand and the matter was remitted for a retrial before a different judge.

1. In a case of disputed aetiology, the court must factor in the possibility that the cause of significant harm is unknown. That does not affect either the burden resting on the party alleging non-accidental injury or the balance-of-probabilities standard. It does preclude an inference of non-accidental injury merely from the absence of another understood mechanism.

2. The judge was entitled to reject the parents’ accounts and to prefer the metabolic bone expert on the issue of identifiable bone fragility. Those findings did not resolve the central difficulty. Acceptance that no recognised bone disorder existed made the extraordinary presentation of the skull fractures more, rather than less, inexplicable.

3. The judge erred by treating the bafflement as principally that of one expert, whereas all four experts were unable to explain the presentation. She also failed to explain the move from recognising that the fractures’ causation remained a medically unexplained mystery to finding, in the next step, that the parents’ lack of truthfulness supported a finding of non-accidental injury.

4. The finding that there was nothing unexplained beyond current medical knowledge was inconsistent with, or at least insufficiently reasoned in light of, the expert evidence. The omission went to the central issue and was fatal to all the findings, including those concerning the rib fractures. The appellate court could not safely substitute its own findings.

5. The case was remitted for a fresh fact-finding hearing before a Family Division judge. The retrial judge should consider directions for an extensive literature search and for a proportionate means of presenting the expert evidence. The matter must then be determined afresh on the totality of the evidence.

• Court of Appeal (Civil Division). Allowed the father’s appeal, supported by the mother, set aside the findings of non-accidental injury and ordered a retrial: [2012] EWCA Civ 1710.
• Swindon County Court. Her Honour Judge Katharine Marshall, in a judgment handed down on 31 August 2012, found M’s injuries non-accidental and retained both parents in the pool of possible perpetrators. Those findings were set aside on appeal.