Two separate claims, conflated in coverage
The dispute is best read as two distinct propositions that public coverage has tended to merge. The first proposition is narrow and clinical: that Dr Evans, having reviewed material since the original trial, has revised his view on the specific mechanism by which one or more of the babies died — for example, that air injected into the stomach (the “stomach bubble” theory in Baby C) was not the operative cause. The second proposition is broader and forensic: that Dr Evans now considers Lucy Letby not to have been responsible for those deaths at all.
Dr Evans appears to accept proposition one and reject proposition two. He has indicated he no longer believes the specific stomach-bubble mechanism was responsible for Baby C’s death (he is reported to have written a new report on Baby C, given to police months before the public dispute), but he has explicitly stated that he has not changed his view that Lucy Letby was responsible for that death — only how she murdered the infant. He has called claims he has changed his mind in the broader forensic sense “unsubstantiated” and “inaccurate”.
Why a single expert revising a mechanism still matters legally
Even on Dr Evans’s own framing, the revision is consequential. In a criminal trial, a jury convicts on the specific evidence and theory the Crown puts forward. The prosecution’s case on Baby C, as the jury heard it, rested in significant part on the air-injection-into-stomach mechanism that the Crown’s own lead expert now considers was not the cause. The Court of Appeal’s May 2024 judgment, and the original jury verdict, both proceeded on the evidence as then presented. Material revision of that evidence by the witness who gave it is exactly the kind of post-trial development that the CCRC process is designed to assess.
This is not a doctrinal point about whether a defendant is or is not guilty. It is a point about the structure of expert evidence in criminal trials: a jury cannot be asked to convict on a theory the Crown’s lead expert later abandons, regardless of whether that expert still personally holds the defendant responsible on some different basis. If the basis on which a conviction was secured has materially shifted, the conviction’s safety in the Court of Appeal sense can be live even if the witness who shifted his view remains personally convinced of guilt.
Where the Shoo Lee Panel sits
The Dr Evans dispute is independent of, and runs alongside, the February 2025 Shoo Lee International Expert Panel review (see our Dr Shoo Lee biography and February 2025 press-conference transcript). The Panel — 14 international neonatologists with no formal connection to Letby’s legal team — reviewed every count on the indictment case-by-case and identified natural-cause and resuscitation-associated mechanisms for every alleged collapse. The Panel’s conclusion was the more sweeping one: that there was no medical evidence of murder in any indicted case.
A narrow Dr Evans revision (on mechanism only) and a broad Panel revision (on whether there was any criminal conduct at all) are not the same finding. But they are not in tension either. Both are independently consistent with the proposition that the medical evidence as presented at trial does not survive contact with full post-trial review.
What this means for the CCRC application
Mark McDonald, Lucy Letby’s barrister, has stated publicly that the application filed with the Criminal Cases Review Commission in October 2025 is supported by reports from 26 international experts and roughly 1,000 pages of fresh evidence, with more than 50 specialists across neonatology, pathology and statistics willing to assist further. The Dr Evans mechanism revision is one strand within that wider body of material; the Shoo Lee Panel review is another; the Joint Insulin Report on Babies F and L is a third.
The CCRC’s task is to apply the “real possibility” test — whether there is a real possibility that the Court of Appeal would now reach a different conclusion, given the evidence as it now stands rather than as it stood in 2023. The materiality of the Dr Evans revision goes specifically to that test: it is not a defence submission, it is the Crown’s own lead expert revising the basis of his trial evidence. Whether that, in combination with the Panel review and the other strands of new material, crosses the “real possibility” threshold is the CCRC’s decision to make.
What now
The public dispute about how Dr Evans’s position should be characterised will continue. The legal question — what weight, if any, his revised view carries in the CCRC’s assessment — is being handled by the Commission on its own timetable. The dispute is unlikely to be resolved in public; if it ever is resolved with legal force, it will be in a Court of Appeal judgment following a CCRC referral.