Bullshit. If you write something and publish it to the world, you can't just take it back. You can edit it, publish corrections, or clarify your position, but you can't un-publish something unless you get lucky and no one noticed before you deleted it.
Adams has been on the internet long enough to know better. And honestly, he's made a habit of putting his foot in his mouth in the past few years. It was just a matter of time before he said something really stupid, like this.
Honestly, what shocks me the most is that he doesn't have some sort of editorial review process. The man undoubtedly has a publicist of some sort... for someone that well known to have no one between him and the publish button is completely insane.