Having read the article and especially the lack of scientific rigor in the theories put forward by doctors regarding air embolism and insulin, I think she should have been given the right to appeal.
It sounds like the babies were reaching the nurses in very poor shape following poor maternal care and there were then not enough nurses as well as doctors with the required clinical skills. This is acknowledged and the hospital no longer attempts to care for these babies which is an admission of sorts that they were unable to provide safe care at a systemic level.
It is interesting that the drop in deaths coincided with the hospital acknowledging that it couldn't provide safe care for babies as sick as those cared for by Lucy. Her departure may have had nothing to do with that.
I can imagine writing the kinds of things that Lucy wrote as notes if I was traumatised by hearing allegations. It's an odd but understandable response to control the pain by inflicting it. Especially with someone as impressionable as Lucy. She seems to have put all her eggs in one basket (her work) and was therefore vulnerable to losing the respect and acceptance of her colleagues.
It's also interesting that the unexplained deaths were cherry picked to coincide with Lucy's shifts and there were others which didn't; these weren't added to the diagram even after the error was highlighted.
Much was made of special 'codes' in Lucy's diary but any nurse knows what these abbreviations stand for and would also use them.
Lucy's habit of looking up patients seems in a different light if one considers that she seems to have made a habit of googling everyone she ever came into contact with. It is very surprising that no searches were found regarding anything that would point towards a plan to sabotage care. I find it really unlikely that someone as meticulous as Lucy would not research anything around this area before attempting to carry out a crime.
As tiny babies sometimes do die without a clear cause, it seems like it was very difficult for the defence to give evidence against the quality of the prosecution's evidence because the prosecution at least had 'the answer' as opposed to no answer - this is just a psychological trick because there unfortunately is sometimes no answer, or an answer that involves a string of events starting with labour that don't individually seem compelling taken separately.
The doctors involved were clearly emotional as many NHS doctors are - the downgrading of the hospital makes it likely that they were under considerable strain and would have been coping with the difficult experience of personally failing to save patients' lives or provide safe care. It is perhaps easier to believe tragic deaths are the work of one individual as it is a much cleaner explanation and locates blame outside the institution and the other medics.
I don't know if she is responsible but I think she deserves a retrial.