I know there is already a question about undoing a comment flag. However, that question was before there was the concept of flag weight.
I flagged an answer for attention because it contains both A. a copyright notice, and B. a substantial amount of code. I wanted a moderator to take a look at this. However, I also left a comment to the OP explaining that SO's posts are under CC-wiki, and that he had (possibly inadvertently) released his source code under that license.
Now, since I flagged, the OP has confirmed that he did intend to release his code as CC-Wiki, and therefore the flag I placed on the answer no longer is really valid. I want to remove the flag, but there does not appear to be a way to do so. A moderator who does the "right thing" is going to mark my flag invalid, which will negatively affect my flag weight (even though I've realized the bad flag before it ever got to a moderator). It would be nice if I could remove my own flag from the moderator's queue (and therefore not negatively affect flag weight).