What should I do when a user complains about a canned review comment and refuses to improve their post?

Question

I reviewed this question and marked the post as a comment, not an answer. That left this comment automatically:

This is really a comment, not an answer to the question. Please use "add comment" to leave feedback for the author.

In response, the user commented:

nope, file_exists is absolutely ok to use to find out if a directory exists. maybe i should have phrased my answer a bit different, but it's by no means a comment and i won't change it after more than two years.

To which I replied:

That was a canned response from the review tool looking at low quality posts. Whether correct or not, there is very little detail provided and very much appears to be a comment. With additional detail (compare to the accepted answer), this will likely not be flagged for review. -- See also this canned response: While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes.

_{Note: While I used the automated comment about link-only answers, that was poor judgement on my part. This question has nothing to do with link-only answers.}

Is this the proper course of action on my part? Should I probe better for the answerer to improve their post? I don't have the expertise to improve the post directly, considering it may be a valid answer, though still low quality in its present state.

EDIT:

While in the process of creating this question, another user made a similar comment on this answer. Perhaps I am providing incorrect reviews?

EDIT 2:

Here's another response to one of my reviews...

EDIT 3:

To avoid too much chit-chat on SO proper, I've removed my automated comments, and any applicable responses to them, from the questions linked to above.

Answer 1

The canned comments weren't really intended to handle every situation. In particular, the "should be a comment" wasn't intended to address very short or lackluster answers.

In some cases, a short answer is perfectly appropriate. In others, they should be deleted, or down-voted, or have specific technical concerns raised in the comments - but in all of these cases, encouraging the author to post a comment instead is the wrong way to go: a bad answer will generally also make for a poor comment.

With this in mind, we're making two changes to the canned comment screen:

• Additional whitespace below the "No comment" option, to emphasize it a bit (also changing the text to "No comment needed").

• A slightly different wording for the "Should be a comment" option, to emphasize its intended use for commentary.

(with the optional "You can always comment on your own posts, and once you have sufficient reputation you will be able to comment on any post." bit added as-needed based on the post author's reputation)

Answer 2

There has always been that grey line with answers like these. Yes, they are low quality and yes, they could be improved. But technically, they do answer the question, even in such a short form.

In this specific case:

It's quite hard to tell. The body of the question itself already accurately detects if it exists and is a directory, yet is asking how to tell if it's a directory. From the accepted answer, I'm gathering he just wanted a way to make the directory if it doesn't exist so he didn't have to repeat code. If that's the case, these answers are probably completely irrelevant.

I would also argue that those answers are incorrect. file_exists() may work for directories as well, but it will also return a false positive if it's just a file that looks like a directory. In that case, the rest of his code would fail.