Why was this First Post deleted even if it does not deserve deletion?

Question

I was reviewing First Posts today and stumbled on this answer as a review audit. To me, it seems like such an answer would be allowed as:

• it isn't spam or offensive,
• it is an answer, as it eventually describes how the answerer solved the problem in the question, and thus it isn't eligible for flagging as "not an answer", and
• it isn't low-quality rubbish that is unsalvageable by editing and thus deserving deletion, so it isn't eligible for flagging as "very low quality".

I think it got chosen by the system as a known-bad review audit because it was downvoted once and then deleted. The downvote seems possible to me as the answer could be wrong, but I think that the post was deleted in response to a flag and moderator error, as this is an answer that does not seem like an answer at first glance, but is actually an answer (if you're willing to thoroughly read it). I've incorrectly flagged such answers before and the flags have been "declined - flags should not be used to indicate technical inaccuracies, or an altogether wrong answer", which I think should have been done to this answer.

Answer 1

You picked "No Action Needed" on a post where at least an edit would have been the action required.

It's not fine as-is, as the entire first sentence should have been at least edited out. That is the second least that would be expected.

It's not clear either through all the introduction that it's something other than a comment. Downvote would have been a suitable action here and the least you could have done.

Choosing to do even less than that fails this audit.