The Vatican has changed course and declared today that Holocaust-denying Bishop Richard Williamson “must absolutely, unequivocally and publicly distance himself from his positions on the Shoah,” or Holocaust.
Good for Pope Benedict XI, admitting error that way.
Oh, wait — that may be over-stating it. The statement asserted that Willamson’s views were “unknown to the Holy Father at the time he revoked the excommunication.”
Rabbi Marvin Hier, founder of the Simon Wiesenthal Center in Los Angeles, said that while he took Benedict at his word that he didn’t know about Williamson’s views, a few keystrokes would have given the Vatican all it needed to know:

“If they Googled the name `Bishop Williamson,’ they’d find out he was a Holocaust denier. This did not require advanced research at the Vatican Library or Oxford.”

This raises a theological question: given the doctrine of Papal infallibility, when is he allowed to admit error? My understanding is that Papal infallability only referred to his pronouncements on official doctrine, so in this case he could have simply said he’d made a mistake without causing a theological crisis.