I agree that the the unexplained and unexpected collapses were key to the case. However the statistical report by the RSS about health care killers does explain that increases in deaths can occur purely by chance, or for unknown reasons. The Telegraph article points out that one rise in baby deaths in a hospital was eventually found to have been caused by them changing their supplier of infant forumula. An example of multiple factors converging would be:
The hospital was struggling, and was understaffed + they taking in more babies with serious needs + they were admitting more ill babies because the maternity unit was not adequately monitoring pregnant mothers.
That is the defence case. Now I'm not saying that's what I think. But I think it's important to know who was present for all deaths on the unit. Because if there were an extra 8 deaths in the June 2015-June 2016 period that Letby wasn't present for, then that suggests there was something else going on at the hospital causing the spike in deaths (as 8 is still very high). If she was present for a majority of the extra deaths, then that raises questions as to whether she was involved in those too. After all, the fact that she hasn't been charged for them just means there wasn't enough evidence. Perhaps she was more subtle. I think it's important to know either way, because if it was confirmed she was present for them, that would be the end of people like Richard Gill's argument.