It sounds like you're implying that when someone posts something on the internet, when you're evaluating the usefulness of that information, you should ignore anything else they wrote previously. Frankly I don't care all that much about Ben's motivations behind calling out the author here, but I read both blog posts as they came out, and the lack of attention to detail in the first post definitely affected my opinion of the second post. I don't think a lack of participation in the first HN discussion means you're disqualified from participating in the second one using information from the first.