I am a mod, newly diamonded, and still learning the ropes. I added a test flag onto a post in my site's meta, to see what would happen on my side of the world. Sure enough, the flag came up in the queue, and to my surprise, I was able to immediately mark it helpful. While I understand why mods might need to flag (rather than immediately act) in case they're not sure, I'm not sure when it would ever be helpful to let them mark their own flags as helpful.
I don't necessarily believe that anyone who got to the stage of being a diamond mod would abuse this just for a stinkin' badge or two, but why is the option there? Am I missing a possible usefulness?