I don't think its quite fair to label this a personal attack, and I don't agree with it getting flagged.

Your link also states "Please respond to the strongest plausible interpretation"

Both their parent and GP were talking about reading conflicting things. Reading around to get a better sense of the truth of the matter would seem, reasonable.

Of course a less pithy comment, where the meaning was clear would be best of all.

Perhaps it would be better to call it a shallow dismissal. Those are also in the guidelines: https://news.ycombinator.com/newsguidelines.html.

Yes that seems reasonable. :)