I flagged a post for closure (not as a duplicate). When I went again to the flagging dialog it correctly displayed that you have already raised this type of flag but this text was also displayed under the it is a duplicate option, which is misleading because I didn't flag it as a dupe.
I'll not term this behavior as incorrect (but misleading) because I understand that even after flagging for closure (as OT or Dupe), I can still flag the same post as spam, vlq, etc. However, I believe that the text should be displayed under the appropriate option.
