I was looking through the >10k flag queue and saw a valid if not particularly good answer that had been automatically (and correctly) marked as an exact duplicate of another answer. Now, while the two answers (given to different questions) were indeed exact duplicates of each other, they were both written by the same user.
So, what we have here is not a case of plagiarism, the user simply considered his answer to be applicable to both questions (not dupes by the way) so he/she copied it over.
My first instinct was to flag as "invalid flag" but on the other hand, it is true that this is indeed a duplicate answer. Do we have a policy on this? If not, I suggest that such cases be allowed, I see nothing wrong with copying your own answer if it also fits another question. Copying other people's is a no no of course.
PS. I am not linking to the actual posts in question so as to not attack the user, if you feel that the links are necessary, let me know.