I'll go ahead and vouch for it, I can't speak to the bug specifically, but everything they've said tracks, and I have a really funny similar story (different orgs).
It's odd, and not what I heard much about FAANG say 5 years ago, but it is what it is.
Among root causes:
- people hate tattletales
- everyone is overworked.
- no second-level manager has enough time or upside to run an investigation every time a first-level manager says "no they forgot about {concurrency|tps report v2.1|memory use}" and another first-level manager, not responsible for the code, says its fine.
- hell, your first-level manager doesn't have upside because it's just conflict. If you got someone knocking around for you, you got a good one.
EDIT: Here's a thread with similar tales. https://news.ycombinator.com/item?id=36853039