I recently flagged an answer because generated by AI.
The flag was declined because they found no evidence of it:
But there is evidence, because at the beginning of the answer it is written it is got from an AI:
and in the comments it is reaffirmed:
Which other evidence is missing?
I was the one who declined the flag; here are some of the considerations I had:
We (TeX.SE) don't have any policy on AI-related posts.
The answer didn't seem off-target nor was it wrong.
The answer came from the OP (who mentioned through comments that it works for them).
Based on the above I made a choice from the following list of options when declining a flag:
Flags should not be used to indicate technical inaccuracies, or an altogether wrong answer
A moderator reviewed your flag, but found no evidence to support it
Flags should only be used to make moderators aware of content that requires their intervention
Using standard flags helps us prioritize problems and resolve them faster. Please familiarize yourself with the list of standard flags: see What is Flagging?
Other: (custom comment)
The second option seemed appropriate at the time: I reviewed it, didn't think the use of AI was a problem, nor did we have something in place to prohibit or even discourage it. So, the flag itself wasn't supported, nor the statement in it... Nothing against you.
In answer to your question of whether there is a way to reply to a declined flag: No, there's no official way. Options include chat or the child meta; you followed the correct route.
I, personally, had/have no objection with AI answers supporting the needs of the community. Based on the assumption that answers are often tested, at worst only by the OP, but at best by the rest of the community, there will be some form of communal vetting of whether or not the answer is valid... and these types of things can therefore be dealt with by the community (through, for example, flagging content as Low Quality so it ends up in a review queue where others can provide their opinion; alternatively, through voting).
While the answer in question explicitly mentioned the use of AI in the generation of some of the code, this may not be the case in general. So, identification of AI-generated content and its approval/disapproval should be handled by the community as a whole. And the best way to achieve this is through voting.
Here are some different thoughts on the process:
If the question was answered without mention of AI involvement (whether or not there is some policy in place), do you think you would have handled the situation differently?
There are often questions on this site asking to create something (an image, or a table, or some structure, often in a do-this-for-me fashion), which is then answered - literally - with "Like this?", followed by some code... could those also be coming from AI-generated prompts?
