The comment was deleted by a CM since they(correctly) felt it was an attempt to post an answer as a comment, but upon reflection, the mod team decided it should be undeleted because we allow comment-answers in some cases.
Cases where we allow comment-answers are:
- When we know answer but lack references. [Such is the case in the said link of the question post.]
- When we receive valid convert-answer-to-comment flag.
However at the same time we would like to remind that it is not a good practice to continue posting answers in comments as per general SE policy.
A general note for every user:
Help section on comments already covers what's allowed and what is not. If you already know basic stuffs like how to comment, then simply scroll to most important parts "When should I comment?" and "When shouldn't I comment?"