user46609: I raised a duplicate flag on this question, but as the OP pointed out the question I had linked to wasn't actually a duplicate of their question. 
However, when I clicked on the "flag" link there was no "retract" option. I've deleted the associated comment, but the flag remains. 
Is there a reason that type of flag can't be retracted? 
Is there anything else I should do (other than being more careful in the future)?
Screenshot of the pop-up:
(Note: The message about declined flags wasn't there yesterday when I tried this so that isn't relevant.)

user27148: Your flag was handled by the 'Community' user as helpful.
When you flag that a post should be closed but don't have close privileges, it puts the question into the Close Votes queue. If another user sees the entry in the Close Votes queue and decides to vote to close for reason of the dupe you marked, the flag is considered 'helpful' and disappears, and instead there is now a Close Vote from that user.
Looks like that's what happened in this case. Basically, your flag doesn't exist anymore but there is still one vote from a different user to close the question as a duplicate according to your initial flag reason.
It's possible you can see some of this flow if you look at the Timeline for the post: https://biology.stackexchange.com/posts/90222/timeline (or click the little 'clock' icon below the down vote link), I'm not sure what exactly non-moderators see and don't see there as far as their own actions.

46609: <p>I raised a duplicate flag on <a href="https://biology.stackexchange.com/questions/90222">this question</a>, but as the OP pointed out the <a href="https://biology.stackexchange.com/questions/44823">question I had linked to</a> wasn't actually a duplicate of their question. </p>

<p>However, when I clicked on the "flag" link there was no "retract" option. I've deleted the associated comment, but the flag remains. </p>

<p>Is there a reason that type of flag can't be retracted? </p>

<p>Is there anything else I should do (other than being more careful in the future)?</p>

<p>Screenshot of the pop-up:<a href="https://i.stack.imgur.com/pr7gN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pr7gN.png" alt="screenshot of flagging pop-up with no &quot;retract&quot; button"></a>
(Note: The message about declined flags wasn't there yesterday when I tried this so that isn't relevant.)</p>
 27148: <p>Your flag was handled by the 'Community' user as helpful.</p>

<p>When you flag that a post should be closed but don't have close privileges, it puts the question into the Close Votes queue. If another user sees the entry in the Close Votes queue and decides to vote to close for reason of the dupe you marked, the flag is considered 'helpful' and disappears, and instead there is now a Close Vote from that user.</p>

<p>Looks like that's what happened in this case. Basically, your flag doesn't exist anymore but there is still one vote from a different user to close the question as a duplicate according to your initial flag reason.</p>

<p>It's possible you can see some of this flow if you look at the Timeline for the post: <a href="https://biology.stackexchange.com/posts/90222/timeline">https://biology.stackexchange.com/posts/90222/timeline</a> (or click the little 'clock' icon below the down vote link), I'm not sure what exactly non-moderators see and don't see there as far as their own actions.</p>
