[You learn in Medical School something similar to what, I imagine, they teach lawyers. “It is a fool who has...”]
It’s happened to me. From years moonlighting in ERs or being the OIC of a military ER i knew that scaphoid fractures were hard to diagnose on X-ray. When I was an FP resident most of the doctors i the hospital (Radiologists, ICU guys, ER docs) knew who I was ad I enjoyed being treated more as a per than just another resident.
One night my wife was chasing the dog and tripped and “Fell on outstretched hand”. FOOSH. She immediately complained of pain, a brief exam revealed it could well be a scaphoid fracture. I drove her to the ER where she was see by an ER doc I knew. I let him do his job. We chatted briefly but it a word about her case. I knew better. She got the X-ray, the report came back, “Negative” and she was about to be discharged when I said, “Could you wait just a minute?” I strolled over to Radiology and asked the guy on duty, whom I knew, “Can I take a quick glance?” “Sure.”
There it was, a little difficult to see because of the obliquely of the beam. Scaphoid fracture. So I was able to save my wife some disability. She had the surgery a couple days later to screw the two pieces back together again. Principles and policies are there for a reason but should never be blindly adhered to when the error is obvious.