“I was thinking ‘This guy is such a liar and everyone believes it.’”

Joe Summerlin, who was on the helicopter that was forced down, said in an interview that he and some of his fellow crew watched Mr. Williams’s initial story and were angered by his characterization of the events…

Mr. Summerlin said that Mr. Williams’s helicopter was part of a different mission and at least 30 minutes behind theirs. His account is supported by two of the pilots of Mr. Williams’s own helicopter, Christopher Simeone and Allan Kelly, who said in an interview that they did not recall their convoy of helicopters coming under fire. After the initial piece aired on NBC in 2003, Mr. Summerlin and his crew went looking for reporters on their base in Kuwait to tell them about the inaccuracies in Mr. Williams’s reporting. Instead, they wound up leaving notes in several news vans encouraging them to get in touch. Years later, they were still frustrated by Mr. Williams’s recounting.

“When he was on the air on the Letterman show, I was going crazy,” Mr. Simeone said. “I was thinking ‘This guy is such a liar and everyone believes it.’ ”

On Thursday, yet another pilot, Rich Krell, gave a different account, telling CNN that he had in fact flown Mr. Williams, and their helicopter had come under attack. Mr. Simeone and Mr. Kelly strongly disputed Mr. Krell’s account.