Photo with customized setting appeared on a non-friends page????

Hello everyone, I am new here.

All of my privacy settings are set to "friends only". I posted a photo to my wall and clicked on the little lock symbol to restrict access to that particular photo to only one of my FB friends. My friend has FB friends that I am not friends with ("Non-FB friend"). I have been advised by my FB friend that a Non-FB friend somehow saw this photo on the the Non-FB friend's page. I do not understand how this could have happened because I did not "tag" my FB friend in the photo, I only restricted access to that particular friend. The photo does not appear on FB friend's profile or in their photos. Somehow it has appeard on the Non-FB friends page though. It is as if restricting access to my FB friend acted as tagging my friend and somehow overrided my "friends only" setting.

Is there any explanation for this? How can this be prevented in the future? It means that the one photo that i tried to keep the most confidential has been exposed for others to see.

Please help!!

Thanks!!

Have you tried uploading it into an album instead of your wall?

No, I haven't tried that. I was just wondering for future why this happened when it seemingly should never have happened. Thanks.

Facebook has tons of loopholes when it comes to privacy. Try uploading into an album and tell us what happens.