When reviewing code and writing a code comment, each comment produces a notification email. Sometimes if the pull request is larger some time might pass until the reviewer writes the next code comment. In unlucky cases the pull request owner could already update the pull request at the same time the reviewer writes the next code comment. In that case the not-yet-saved code comment will be cleared by OneDev and everything already typed is lost, because the UI refreshes itself once the pull request is updated. That is a bit inconvenient.