Sometimes I read questions on topics that are a little bit beyond my level of knowledge, and I might struggle with a point in one of the answers. I then ask the answerer in a comment to clarify, but for my own sake, not that of the original asker of the question.
I haven't really seen anyone else doing this, though, and I can see how it might be considered to be distracting from the original question. Is it okay to do this?
Note that I'm only talking about other peoples' questions.