Yeah, I have fought with this occasionally. It's one of the handful of "gotchas" you need to think of when designing logging, and interpreting its results.

Sometimes you can improve the situation by sticking things in a bigger memory buffer and tightening control of when things get flushed to disk, but there's always that fundamental "observing the system will change it" problem. Similar issues arise with a debugger too, of course.

Yeah I had to debug some code with 5 threads that were supposed to be synchronized through the use of several semaphores that was a bear to pin down.