I’m guessing even in the best hospitals daytime is when most of all the patient’s urgent needs are met by all the doctors in charge including lab tests, x-rays or MRIs. Daytime is when they review the care plans they initiated and they do adjustments accordingly. At night in the best hospitals, I can only assume they have enough personnel to attend to patients in case of emergencies. But yes, I do think that in all hospitals a patient can still “fall into a crack” especially if that patient is incapable of advocating for himself and there is no family or friend who knows how to properly advocate for that patient.