Society mitigates against honesty by running a blame culture - make a mistake in public office, and you are likely to be pilloried by self-satisfied media reporters and members of the public - people who almost certainly make lots of mistakes themselves, but feel safe in the knowledge that they are unlikely to see them made public.
Add the big risk of someone hearing a cash register ring, and wanting to claim compensation for pretty well any consequence of a public service mistake, and you can easily understand why lots of people are terrified of owning up to their mistakes.
Spotting someone else's mistake, and alerting them to it, can be well or badly received, and lots of people adopt the 'live and let live' attitude. It's a question of context - if I make an error, and accidentally ban someone it's hardly going to change that person's life, but if an ambulance crew messes up it could well be a life changing (or ending) mistake for the patient.
If I am killed because an airline captain makes a mistake when taking off it's not something I am going to be worried about, but my family and friends may well get some kind of closure (that awful word!) from hearing the pilot say 'it was entirely my fault, and I am deeply sorry'.