Because NSFW flairs hide content from users who do not want to have porn show up on their feeds, or otherwise want to avoid content genuinely not safe for work, perhaps more care should be taken to ensure users who flaired posts as NSFW, since doing so can hide the content, even if in no way is it actually NSFW. As it is now, an OP could flair a post NSFW, and then claim it was the admins, thus drawing suspicion on the principles of the admins. Or the admins could flair a post NSFW, and say it was the user, and even if the user denied it, it would his word against the admins. To avoid any possibility of doubts on these matters, and to always understand whether it was a user or admin flairing a post NSFW, I think adding the label suggested in the title, as with deleted posts or comments, would be in the best interests of transparency.