I read that article in the gym. Lumet is a great director.
His "Fail-Safe" is my favorite example of the director's art. Most of the time, most people can't see the director's contribution past fine performances, strong script, excellent filming and sets, etc. "Fail-Safe" has few sets and no action, and most of the movie just shows Henry Fonda on the phone. Yet it is almost unbearably harrowing, gripping and credible--thanks to Lumet's splendid direction and his unerring feel for drama.
Several years ago, George Clooney remade "Fail-Safe" for TV. He did it in the spirit of early TV: B&W, live action. He assembled a great cast, too, including Harvey Keitel, Richard Dreyfuss and Brian Dennehey. I give him great credit for recognizing the quality of the original "Fail-Safe" and for his effort. But, compared with the original, Clooney's version is flat and lifeless. There's where he could have used the director's art.