Scenario: I uploaded one image, viewable to “Friends except Acquaintances.” I tagged 1 friend on that image. That friend did not approve the image to appear on his timeline, so the image never appeared on his timeline. BUT he did not remove the tag.
Result: His friends can still see the image that was on MY timeline, not his, even if they are NOT common friends. On FB or in real life. The notification probably appeared on that scrolling source of chismis on the right hand side of your FB Timeline page of his friends.
Lesson learned: If you do not want anyone else seeing or commenting on an image you are tagged on, not approving the tag is not enough. You must REMOVE THE TAG. You might also want to limit the audience of posts and images that you are tagged in. You can do this by tweaking the settings on Privacy Settings > Timeline and Tagging Settings.