This question already has an answer here:
I flagged this one as "not an answer":
My flag got declined:
declined - flags should not be used to indicate technical inaccuracies, or an altogether wrong answer
Can anyone explain why (for this particular case)?
It is clearly a link-only answer, and the answerer did not provide any information to why this would be useful to the OP. I would understand if they said at least something, that makes it relevant to the question. Then it would be arguable.
Is it just a moderator's error? I am pretty sure to have voted the same way in >100 of other different cases, and they were all accepted.