The opposite sometimes happens. Someone who is very competent and confident in one domain, assumes that competence carries over into another domain and comes a cropper when it doesn't. So I wouldn't suppose that her coming a cropper here means she is bad at her job.

And it sometimes happens that medical staff are brilliant at working with strangers, but go to pieces when the patient is a friend of theirs, eg another nurse. It can help to have a certain amount of detachment, and to consider problems dispassionately. That may have been a factor too: she may have been less good at her own survival than other people's.