NC pressed ED to describe SP's role as a floor coordinator. She was basically the one who went round making sure that things got done and staff were deployed to where they were needed when it was busy.
Which pretty much means that if she left one cubicle to go elsewhere it was almost certainly something that would have been normal and usual, in keeping with her coordinator role.
And more importantly, if the person in charge of coordination, who had never failed the department in 30 years, was now abandoning patients willy nilly, then it wasn't just that patient at risk but potentially the entire shift that was no longer being coordinated. There would have been carnage if things got busy but the coordinator was off sulking in a corner.
Also, given that she was described as stern, and vocal, and responsible for keeping order on busy nightshifts, you'd think that in a large department there would almost certainly be people who had been told off at some point and harboured a grudge who would be delighted to grass her up if she really did start causing problems herself. But they had nothing.
I don't think anyone at all would have believed the patient safety 'angle' was anything more than an 'angle' that KS and DU wanted to push.