Except all of this either did not happen, or has a plausible explanation.
It is proven in emails, published as part of the Thirwell inquiry, that Breary's initial review ignored findings and recommendations made in a prior, external review by the Royal College of Paediatrics and Child Health, which highlighted serious failings on the unit, and instead focused his attention on the nurses on duty. Lucy just happened to work the most hours. Everyone after this just followed Breary's lead.
There is no evidence she altered notes to cover wrongdoing; this is circumstantial. It is totally normal to go back and add annotations to notes taken during emergencies because it is not possible to take notes and properly administer care simultaneously. It was claimed she added a blood glucose level of 2.9 to one baby's notes to cover up insulin poisoning. Medical professionals have since confirmed a blood glucose level of 2.9 is actually low, especially considering the other care the baby received, so this makes no sense. She would add a higher-than-average reading, not a lower one.
Suspicious behaviour is conjecture, and you have to note the fact that Letby had already been pinpointed as the only suspect. People were looking for her to behave suspiciously. This is confirmation bias.
Ask anyone in healthcare if they or a colleague has ever Googled a patient or looked at their social media, and every single one will say yes. You have to remember, carers and nurses spend 40+ hours a week caring for their patients. It is impossible not to form an attachment with them and their families.
Again, we do not know why her defense team didn't use their own expert; they may well have had a plausible, tactical reason, but it doesn't change the fact that it resulted in a trial where the medical evidence presented was entirely one-sided.