I think it's best not to say something is a "lie" unless you have a strong basis for it, let alone asserting it is a "outright lie".
A lie is an intentionally false statement. It involves an intention to deceive. It's highly unlikely that someone on Hacker News would set out to intentionally mislead people who are familiar with the subject-matter and who know how to fact check.
At best they are "wrong", "misinformed" or "mistaken". Although, as said in the first paragraph, I suspect you're actually at cross-purposes with each other.