It could actually just be a result of confusion or laziness.
(You usage of "disingenuous" is almost as a synonym for "wrong". It doesn't just mean "wrong" or "incorrect", it implies that you believe that the comment is intentionally dishonest. If you aren't absolutely sure someone is trying to mislead others, it's a poor word choice. It gets used on HN a lot, a lot more than it should be.)
edit: I do see from the sibling reply that you were more or less right.
(You usage of "disingenuous" is almost as a synonym for "wrong". It doesn't just mean "wrong" or "incorrect", it implies that you believe that the comment is intentionally dishonest. If you aren't absolutely sure someone is trying to mislead others, it's a poor word choice. It gets used on HN a lot, a lot more than it should be.)
edit: I do see from the sibling reply that you were more or less right.