The mayors of New York, Paris and London co-wrote (or co-ghostwrote) this opinion piece, which in an earlier edition contained the phrase, "In our experience, militant violence is vanishingly rare.”
http://www.nytimes.com/2016/09/20/opinion/our-immigrants-our-strength.html
An Editor's Note at the end of the piece claims, "Because of a miscommunication, the phrase, which was added by an editor, was published without final approval of the authors."
So the Times seems to be in the business of adding material without "final approval," or, more likely, it is falling on its sword after the fact to protect the authors, since the phrase probably raised a justified storm of derision for its stupidity.