Just to add a bit of correlation to your post.
I noticed this when I was working on a POC setup.
On my master fog server the files and folders under /images are owned by root.root with a file mode of 777 (realize I may have done the mode 777 when trying to get the master node to work many months ago. I installed 1.2.0 on this and then upgraded to the latest trunk builds over the months.
On my storage node the replicator created the image files (same as on the master node) being owned by fog.fog with a mode of 755. The storage node was just setup with 1.2.0 and then immediately updated to the latest trunk build.
To answer your question about fog being a sudoer, from a security standpoint I would say no. This should remain a low level account.