Many looking closely at it say it was mainly Roberts who screwed up, but I say they both did, and I agree with the comment on Balloon Juice - "Clearly, this means that the inauguration is not valid according to a strict interpretation of Article 5 of the Constitution. I believe that, technically, this means that Ted Stevens is now acting president 'until such time as the oath is properly administered'." Ha. I'm sure they will get right on that. :-)
Article V?
I know it was text you quoted from the other site and all, but if we're being sticklers for details...
I would be surprised if they didn't immediately clear it up once he was off the stage.
Yeah, I know. I saw that too. But as you said, I was quoting...
Of course, I should have pointed out the error in what I was quoting, but I thought it was funnier without that. :-/
Oh, and to be clear for anyone following, the Oath is in Article 2.
And a related discussion on timing:
http://volokh.com/posts/1232483177.shtml