From the look of it through permissions and from what I saw, I don't recall allowing an administrator being able to do this. I would imagine some kind of hook would have to do the trick for this kind of thing (and I wasn't able to find one that could do this, at least from a 10 second search). You obviously can make it so the regular member can not see the board, or at least can see the board and view the threads but not be able to post in the board.
You could perhaps make another uploading board for regular members where all content of it is moderated and people in an uploader usergroup will have another board where they can post as they wish without the moderation setting being on. I personally wasn't able to find anything past this though, sorry.