The above questions have various different ways of dealing with this--but they're from the "ordinary user" perspective. My question is, when a moderator comes across a "duplicate answer", what should he/she do?
By "duplicate answer", I mean one that is posted a significant amount of time after the "original" answer (this eliminates the case that both users worked on the answer more or less simultaneously and there was no plagiarism involved) on the same question. It should not add much more to the answer pool than the "original" answer.
What should the policy be for dealing with such answers? Should we just downvote+comment? Or is it OK to comment+delete?