My mentors taught me that a second opinion was to be considered as a service to colleagues and patients alike. In an ideal world, where medical care is given with honesty and integrity by practitioners who are well-trained and keep their skills and education current and evidence-based, when complications or disappointing results occur, patients will have been prepared for that possibility. It is when some part of that recipe is missing and expectations and reality aren’t matched, that the doctor-patient relationship starts to fray.
In these circumstances, an honest, impartial opinion may be al that is needed for a patient to be reassured and continue with their doctor to address whatever is needed.