I flagged this question on Ask Ubuntu as a duplicate. A comment "Does this answer your question...." was auto-generated. For trying things out, I retracted my flag. Now, I can't delete that comment. Since I'm a low reputation points user, I can't edit my comment as well.
Screenshot for reference:
I'm aware of <50 reputation users can't delete comments that were posted on their behalf, but that's a bug report that was marked as "by design". The explanation for having it designed that way is because users without privileges supposedly wouldn't be able to restore/repost such automatic comments if they deleted them, and that in the admin's opinion, new users usually aren't aware that they can retract flags.
However, this is a feature request to change the design to allow low-reputation users to delete comments created on their behalf. There are also other cases where low-rep users end up with comments posted on their behalf, such as if they trigger the "trivial answer converted to comment" script or if a moderator converts one of their answers into a comment; it doesn't make sense to disallow deletion in those cases, and in the first case, they can repost the comment. Also, just because most users are unaware of the flag retract functionality doesn't mean we should shut it out for users who are aware.
This has come up in another interesting way: a new user posted an answer that triggered the trivial answer comment conversion feature. For some reason, they didn't see the redirect and notification from the feature (maybe it didn't load for them for one reason or another), and so they thought that their answer went into the void somehow, and tried reposting it two more times, resulting in three duplicate comments which they only noticed later. They were unable to delete the duplicate comments themselves, and couldn't flag the comments since they didn't have 15 rep, which delayed the comment cleanup.
This also affects users who make comments while having the privilege, but later lose it (e.g. due to a bounty): they can't delete their own (non-automatic) comments posted back when they had the privilege.