From a review of Kalb's One Scandalous Story:
The highlight of Kalb's book is his careful dissection of one of the scandal's great non-stories: the allegation that a White House staffer--perhaps a Secret Service agent--had happened upon Clinton and Lewinsky in flagrante in the Oval Office. First reported by Jackie Judd on ABC News, several permutations of the story ricocheted around the media universe for days, eventually forcing embarrassing retractions from two of the nation's most prestigious papers, The Wall Street Journal and The Dallas Morning News. The false rumor captures the pitfalls journalists encounter when they ignore the by-the-book approach Kalb so sternly advocates.
The heroes in this episode are John Broder and Steve Labaton of The New York Times, who spiked their own story about the tryst's eyewitness at the last moment when they suddenly realized something their competitors did not: Their "sources" (four of them, in fact) were not really sources at all. The pressure on the pair was intense, not least because their story looked big enough to offset the Post's having scooped the Times in breaking the Lewinsky story. Yet careful last-minute spadework indicated that rather than four knowledgeable sources, what they actually had were, in Kalb's words, "four different people who seemed either to be echoing the Judd report [from ABC News] without any independent confirmation of their own or conveying and then embellishing a rumor they had heard about an agent `stumbling' upon the president with a young woman."
Like an echo chamber, the combustible scandal atmosphere had ricocheted a single rumor in so many directions that it seemed to many as though it were being confirmed from numerous sources. Only uncommon restraint and exacting self-scrutiny kept Broder and Labaton from falling into the trap that snared their peers. Later they learned that each of their four "sources" might actually have picked up the rumor from the same individual, former U.S. Attorney (and ubiquitous talking head) Joe DiGenova.