A little while ago I flagged this answer as "Not an answer", as it is just a bunch of seemingly random screenshots posted by someone who was neither the OP nor the author of the other answer to the question. There is no context to the screenshots, or really any text whatsoever. It doesn't seem like an incorrect answer, as that should just be down-voted. I don't think it's an answer to a different question, although I could be wrong. I didn't flag it because I disagree with it. It's just a complete non sequitur.
However, the flag was declined - "flags should not be used to indicate technical inaccuracies, or an altogether wrong answer"
I've read through the relevant FAQ item on Meta.SE and some other related posts, and I don't think this fits in to the When should I not use this flag? section of the answer. Should I resubmit this as a custom flag and explain to the mod my thoughts, or just let it go and let voters have their say on its usefulness?