@Yam Yeah.
I have a feeling that the type of games one’s been on weighs into the irritation factor here. If there’s only 12 skills and they’re all pretty broad, you can justify an “I was doing this off camera” in a lot of ways. If there are 100+ fairly niche skills and a not-niche person is suddenly an expert in them, that breaks immersion a bit more, and cheapens the experience for the players who were focusing on that niche ahead of time.
For me the issue isn’t that Gun Man is going from level 3 to 4 in Shoot Gun mid-scene, it’s that Gun Man is going from 0 to 85 in Computer Surveillance in a scene that I finally ran specifically to please the one person who has been steadily leveling Computer Surveillance. This did not happen a little bit. This happened a lot. Crunchy traditional game where poor sportsmanship may be rampant, etc.
This whole phenomenon does not bother some people, which is fair. It does irritate me, which is just a personal preference. I have seen too much of it from too many people who weren’t fun and weren’t trying to make IC sense. I find it annoying. I don’t like it. Peeve.