Duplicate flag lists "you have already raised this flag" after flagging as "Unclear what you're asking"

Question

I recently flagged a post on SO as "Unclear what you're asking". Afterwards, for whatever reason, I clicked flag again and found this:

Is there any reason it says I've raised a duplicate flag too when I'm positive I have not? Is this a bug? The question, as of 2:56 PM UTC, 11 September, 2013, has only existed for 26 minutes and the flag doesn't exist in my flag history:

Note: There are several similar questions:

• "You have already raised this flag" Well, not really
• No, I haven't already raised this flag (not here, anyway)

The first was never answered and the second is unrelated as it appears the person asking did, in fact, raise the flag they assumed they hadn't raised.

Answer 1

While both of those flags would generate a different reason in your flagging history, they both generate the same type of flag: recommend closure.

This would be very much in line with not allowing users to vote to close twice. Allowing you to flag to close twice would follow the same premise. You're not even allowed to vote to close a question you had previously flagged for closure. So this seems very much by-design.

Answer 2

The message has been updated to;

You have already raised this type of flag

Both duplicates and "another reason" off topic reasons are the same type of flag (recommend closure) and are handled in a similar way; for example both go to the >3k close queue.

Similarly spam and offensive flags are of the same "type"; for example 6 of either will autodelete a post because they are of the type "recommend deletion".

Rationale
Casting additional flags of the same type serves no purpose as they behave in the same manner, as such only one flag from each type can be cast