Every doctor knows this. Furthermore, every doctor knows that sometimes, no matter how hard everybody tries, the vessel will still get nicked. I urged my resident to put it behind her, told her there was nothing else she could do. Then my gynecology rotation ended two weeks later. I'm still not sure whether she has ever forgiven herself.
Most doctors go into medicine, on some level, to help others.
However, most doctors are also rational people. Yes, they don't want to lose their livelihood and source of income. Yes, they don't like to be wrong. But when they make a mistake, most doctors know that they've erred, have learned from it, already feel terrible enough about it, and can't do anything to change what they did. Of course, one answer to this question is that lifting the shroud of silence would allow those doctors too intimidated by its tradition to finally relieve themselves of the burden of carrying around past mistakes.