Here's a fun story from my time at Mozilla. Remember that time accidentally sent a notification to all our mobile users that just said "monitor"? I was sent to run the retro on that, see what we could learn and prevent a recurrence.
It would have been pretty easy to say "this person screwed up it's their fault" - and sure a human made a mistake - but I am an absolute believer in blameless, in-depth retrospectives as _the_ essential tool of safety, reliability and personal growth. So.