He used a subscriber account to read the story early, type up a rather lengthy response, and then posted it using a brand-new account. You can tell this because his comment was posted in the same minute as the article, yet clearly took more than one minute to post. Astroturfers seem to use this method to post scathing commentary about company X (Google seems to be the most common), while avoiding the permanent karma hit (and recognition as an astroturfer) to their subscriber account.
It could also just be a troll posing as an astroturfer, and using this method to irritate the community. That distinction is largely irrelevant, however.