I'm doing contract work at a big multinational company, and I saw a syntax error slide through code review the other day. Just, like, too many parenthesis, the function literally wouldn't work. (No, they don't have automated unit tests or CI/CD. Yes, that's insane. No, I don't have any power to fix that, but I am trying anyway). It's not hard to imagine something more subtle like a memory leak getting through.

In my experience, people don't want to say "I think this is all a bad idea" if you have a large code review. A couple years ago, a guy went off and wrote a whole DSL for a task. Technically, it's pretty impressive. It was, however, in my opinion, wholly unnecessary for the task at hand. I objected to this and suggested we stick with the serviceable, supported, and interoperable approach we had. The team decided to just move forward with his solution, because he'd spent time on it and it was ready to go. So I can definitely see a bunch of people not wanting to make waves and just signing off on something big.