I should imagine that if there was negligence in this matter it would fall to one or perhaps two members of the medical team rather than the whole team depending on how they work.

Personally I not only feel for the lady and her relatives in this matter, but also for those on the medical team who are feeling bad about this incident.

Statistics won't define genuine mistakes or willful disregard, neither could they diminish the usefulness of bracelets as the more protection the better. If anything it may be more useful to track the reliability and practices of those directly involved and take steps from there.