Or anything that breaks the norm really.

I recently wrote something where I updated a variable using atomic primitives. Because it was inside a hot path I read the value without using atomics as it was okay for the value to be stale. I handed it the code because I had a question about something unrelated and it wouldn't stop changing this piece of code to use atomic reads. Even when I prompted it not to change the code or explained why this was fine it wouldn't stop.