This is a true story...
My father and stepmother knew that my baby brother was going to have to be born by Caesarian. Nonetheless, flush with parental enthusiasm, they decided that Dad was to take photos of the event. The roll of film was duly taken and sent off to be processed, however when we got the little package back we found it to be full of someone's holiday snaps. There had been a mix-up and someone else was, at that very moment, finding photos of an operation instead of beaches and smiling faces...
When the developers arranged a swap they told us the other people had been "very upset."