For some reason, facebook's safe_image.php script isn't generating thumbnails, properly. It's generating a 1x1 image... even though the correct image is linked in the script's parameters. Example:
<img class="img" alt="" src="https://s-external.ak.fbcdn.net
/safe_image.php?d=AQBtrCt_Es_KsED0&w=90&h=90&url=http%3A%2F
%2Fwww.southlapatriots.info%2Fimages%2FScamra%2FJayCastilleCouncil2.jpg"
The linked image is correct, but it is still only generating a 1x1 image.
Got the same problem today, in my case was an https issue.
I automatically redirect every http requests to https, and while the browser works this out normally, FB's safe_image.php doesn't. If you have such redirect as well, you may want to disable it for just your og:image file.