To the best of my understanding, "not an answer" flags should send an answer to the "low quality" review queue. Then, if someone disagrees with the flag, it gets "disputed".
An answer I flagged as "not an answer" received "declined - flags should only be used to make moderators aware of content that requires their intervention". Which makes sense - "not an answer" doesn't need moderator intervention, it needs to go to the low quality review queue.
Only it seems the answer never got to the "low quality" queue - what I see in that queue's history is that last time anyone reviewed anything in that queue was yesterday.
So what happened?
(Question is similar to this one from 2012, but I'm not sure if flags worked the same way back then.)