Do people actually do this? It seems silly and childish. Although I’ve never had a boss that needed to find an error.
I think that is key. A great mentor early in my career pointed out to me: "A" rated people need to work for "A" rated bosses. It's possible to have a "B" or "C" person work for an "A" boss, but when you put "A" people under "B" or (god forbid) "C" bosses, all kinds of problems ensue.
[I've personally experienced that situation only once, and swore never again.]
Actually, I bet you could have an ok workplace with “A” workers under “C” management. Or maybe the “C” turns into an “A” if they manage to hire good people and get out of their way…
But the problem with "C" managers is that they won't judge "A" work as "A" work, won't understand why some of the "A" work is important, and will get in the way of the "A" engineers, making them go down "C" paths.
A "C" level manager brings the whole team down to "C" level and destroys the morale of "A" and "B" workers while they're at it.
An "A" level manager can guide everybody towards "A" level work.
If you do that, you'd do me a favour.
I could see the same dynamic in reverse when I had to propose stuff to the central tech team at that employer.
It is my firm belief that it isn't likely to find a the flaws in anything important (except for the obvious flaws intentionally left that other posters have mentioned) in the scope of a meeting. Once in a while you will by chance, but even if there is a flaw it needs some to look and think. People who think out loud often drive the meeting in the direction they are thinking and if there happens to be something in that direction they will find it sooner - but they miss the other directions others would have gone thinking in because they directed the thoughts of everyone.
You want something from someone else, at some cost to you. If you let the other party decline something you seemingly want, they have the impression that they're giving up less or are getting a better deal.
It's just compromise. Except you never actually wanted the thing you're compromising on and the ltjer party never cared about. It's just ticking the psychological boxes.
Some people will go through great lengths to find a flaw in whatever they look at, and once they see one they will keep asking about it continuously even if fixing it is something very counterproductive.