<p>Additionally, per:</p>

<p><a href="http://meta.stackexchange.com/questions/82134/micro-refinement-to-notifications-for-comments-of-others-posts">Micro-refinement to notifications for comments of others posts</a></p>

<blockquote>
  <p>If a user comments on their own post and there is only one person who has previously commented, then that person should be notified when the author comments even if '@user' is not specified.</p>
</blockquote>