Yes, that is what I have in my code.
My trouble shooting test was simply to comment out that FilesMatch section – then the image can be fetched by Google webmaster tools.
So I assume the referrer rule must be the problem. I can’t seen anything in the BPS log although my 403 log code is still not working properly, (I haven’t been able to fix that yet but that’s a separate issue). I can see errors in my cpanel error logs when I use webmaster tools to fetch an image (https://www.google.com/webmasters/tools/googlebot-fetch).