Yours is "Twitter's Down" while this is a link to an article; not that yours necessarily should have been flagged (although that's a community decision so apparently several people thought it should have been) but they're not the same post.

He should've used the Tell HN: tag since he didn't link to an outside article.

Yes I can see that (not sure if it's because I have `showdead` enabled or not, who knows). My point stands, I think.