Oh, other people in other threads sometimes have different tendencies (especially in fast-moving live threads), but I do try to click "Post Reply" at the appropriate post. For example, this way the "To [post number]" and "View Replies" links actually work as intended.
My intention also would've been clearer if I followed my usual practice and quoted the earlier post. For a number of reasons that were all on what you may call a technical side, such as formatting and overall length, I decided not to do so in this case. In retrospect, though, I've thought of a few alternatives, such as posting a summary of the earlier post. (I've always appreciated posts that quote earlier posts in a way that clearly shows what's being quoted.)