In any event, now comes the theory that Roberts was trying to invalidate the Obama presidency.
As a bunch of folks pointed out when whitehouse.gov flipped to reflect President Obama being the President at exactly 12:01 p.m., the Twentieth Amendment makes the transfer of power automatic regardless of when the administration of the oath takes place. The President need only take the oath "before the execution of his office."
Is there any impact from Roberts slip up? Conceivably, any acts taken before he got re-sworn using the proper text would be unofficial acts and only properly executed after the oath was administered. I suppose one might conceive of a case where this would matter, but it is rather difficult. Further, it is not as if the President did not vow to protect the Constitution, the critical element of the oath. The question -- if any court ever decided someone had standing to challenge -- would be whether the matter is subject to strict formalism or whether a statement reasonably close to the wording, containing the critical elements and with clear intent to take the correct oath, and remedied reasonably swiftly thereafter, is sufficient.
But in no case could it invalidate the Presidency, as Roberts would well know.
We have real enough issues before us. I hope progressives are wise enough to learn from the example of the Republican base -- which has become obsessed with the purported deep-laid plots of the liberal elite to destroy the real America -- to avoid getting sucked into these self-destructive sideshows.