I wish there was some way to directly respond to mod comments on a flag... Anyway...
I was under the impression that "not an answer" encompasses "answers" that merely link to existing ones without adding anything new. So how is it that when I flag such an "answer", the flag gets rejected and yet the post is deleted for exactly the same reason? I did not evaluate the answer for technical accuracy or anything, the flag was purely meant to indicate that it should have been a duplicate vote or a comment instead of an answer. A comment stating the same was left for the poster as well.
As it turns out the reason the poster thought the linked answer was a duplicate was technically inaccurate, but who cares? The flag was raised due to the nature of the "answer" and not to indicate that it was a wrong answer to the question, and so it's weird to see it being declined when the mod actually agreed with me!
(Yes, I know this sounds like a lengthy whine and one rejected flag has no adverse effect etc. I'm not looking for an apology or something equally ridiculous, and indeed no response is required. This can be considered just a note for mods to evaluate flags carefully. Sometimes we too lack the time to leave explanatory comments with a flag, but the default options exist and are carefully selected for a reason.)