Concerning the use of the image on Facebook, if it was, in fact, never posted on Facebook itself, then yes - the rightful owner would have a case.
In the thing you are required to agree to to create a Facebook account (ie. Facebook's Terms and Conditions) it states that any and all media that is posted on Facebook immediately becomes the property of Facebook and can be used whenever, where ever, and however they want without express permission. When I found this out, I immediately took down all of my poems and artwork I had on my Facebook.
One man's wrong lead is another man's counter canter.
"Adjust Your Pleasure"
2006 Medicine Hat Paint Gelding