Medical statistician Jane Hutton submitted a report arguing that the Crown's central evidence—that there had been an 'unusual' pattern of illnesses—was of 'no value' because no statistical modelling had been done to show that the pattern was unusual. She found the 'pattern' method to be at grave risk of bias. In spite of the complexity of statistical analysis and its proper use, the Court of Appeal refused to allow her to give evidence at the trial. Lady Justice Hallett stated: ‘We are satisfied the jury was entitled to, and perfectly capable of, drawing proper inferences from the evidence that this pattern of events was as a result of deliberate action rather than mere chance’.