I'm curious, too, as to the details of the situation. Was the patient at home, with family monitoring symptoms? Or was it in a clinical setting? It seems there would be, as others mentioned, more safeguards in place to prevent this scenario, i.e. more frequent monitoring. If not, putting them in place for the future may give you peace of mind.
I've had patients, too, whose symptoms were just plain hard to control, with endless hours and multiple med changes needed. In most cases, the family appreciated the fact we stayed in the ring fighting for their family member's comfort, even when it was elusive.
Afterward, I analyze the case with my colleagues and do my own research to see what, if anything, I may have done differently to relieve symptoms more quickly. I try to redeem the experience by incorporating the lessons into my practice, so my future patients can benefit.