I am not so sure this completely discounts the statistical relevance of when Letby joined, more infants died. When she was reassigned from the day shift the the night shift, she brought along the same pattern of deterioration for the infants. I am not convinced that there being "no medical evidence" discounts these facts, but still, I wonder if it is possible that Letby is single most unlucky nurse in history and truly freak accidents happened on her watch by chance. Its hard to say.