She has an attachment to that memory, because it's the last hours of her baby's life and she wanted to feed him, she was hardwired by very strong maternal needs to nurture her babies. That memory will probably be seared on her brain forever. Nobody else that night had that mother's experience, for them they did not know there would be a need to memorise it, or recall it ever again. Staff do the same thing over and again with all mums, helping to express milk, it's just not memorable, unless it's an event out of the ordinary, like an emergency call is, which then gets recorded in the patient's notes. No one is going to remember the time a mum turned up to feed her baby, it's not a stand out event, especially when she was there earlier and later as well.
There is no one to corroborate LL's notes, which are off by one hour with the feeding regime, and mention cares which the mother had already done before LL's shift started, and mention a doctor on a different ward who has no record of advising LL to omit the feed. If it's a choice between all of those factors weighing in anyone's favour, and corroborated by the call to the father, I know whose account I'm going with. It's not LL's, for all of those reasons.