Am I reading something wrong, the twitter link leads to an article from May 2011. This isn't current.
The article is old but the tweet is new. They usually link to an article to mark the context of the tweet.
In my niche I have seen the sites ranked #1 & #2 fall to the second and third page. Who knows why??? My site that used to rank #1 is still on page 50. Luckily I have moved my business away from organic SEO so don't really care anymore.