When I first came across this question, it was closed only temporarily and I assumed that it was not a duplicate (otherwise it would have been closed as one). So I went on and did my research and posted an answer. But then a rushing mighty wind came and I was downvoted because the question WAS a duplicate. [I don't see why this other question was not considered as a duplicate, when it was asked on two sister sites. This matter was addressed here on Meta.]
After less than half an hour, after a little discussion in the comments to my answer, the question was closed as a duplicate.
While I understand why a duplicate question is closed, I still wonder: is this enough reason to downvote an answer that is perfectly correct and upvoted by others?