Roger Clemens trial: Andy Pettitte admits doubt about talk WASHINGTON - New York Yankees pitcher Andy Pettitte threw the perjury prosecution of his friend Roger Clemens into disarray Wednesday when he testified that he could have misunderstood a conversation with Clemens about human growth hormone. Pettitte said he thought Clemens told him sometime in 1999 or 2000 that he used HGH, but he admitted under cross-examination that he was hazy on the details. "I could have," Pettitte replied. Attanasio then asked Pettitte if he had only 50-50 confidence in his memory. "I'd say that's fair," he said. Lead prosecutor Steven Durham had sought to demonstrate Tuesday how close Clemens and Pettitte were to build the credibility of an important witness. Pettitte said that he saw Clemens, who is 10 years older, as a role model and that when he joined the Houston Astros in late 2003 he picked the jersey number 21, the same as Clemens had worn with the Boston Red Sox and Toronto Blue Jays. But in admitting doubt about the HGH conversation, Pettitte has left the prosecution's case badly weakened, trial-law experts say. "He's basically their key witness, because he would have, quote, 'no reason to lie,'" Joseph diGenova, a former prosecutor in Washington, said. This has always been a difficult case - I think this is pretty much it. With the jury out of the court, defense lawyers asked U.S. District Judge Reggie Walton to strike Pettitte's testimony in its entirety. Over protests from Durham, Walton said he would consider it. The only other person expected to testify that Clemens used human growth hormone is Brian McNamee, a former strength trainer, who says he injected Clemens with the drug, as well as steroids, and saved needles with the pitcher's DNA. But much of the evidence for the report came from McNamee, and in his opening statement Clemens attorney Rusty Hardin signaled that he would strike directly at the former trainer and challenge the DNA evidence he provided. Hardin had also hinted that Pettitte's testimony would not be that damaging to Clemens. Marcellus McRae, a former federal prosecutor now in private practice with Gibson, Dunn & Crutcher in Los Angeles, said the prosecution was probably caught off guard by Pettitte's hedging. "That to me is absolutely the most intriguing: Did anyone know this was going to happen?" he said. And if they did know, what was the point to him testifying? Durham also asked Pettitte about a 2006 article in the Los Angeles Times that said Pettitte and Clemens were named in an affidavit as having used HGH. Pettitte said he was informed about the article before it appeared. In 2007 unsealed court documents showed the article to be inaccurate - neither Clemens nor Pettitte was named - and it was corrected by The Times. Walton told jurors not to consider it as evidence in the case. The focus now shifts to the DNA evidence. It will have to bear additional weight, but John Goldman, a sports-law specialist at Herrick, Feinstein in New York, said that if it can be made to stand up, the prosecution could recover from Wednesday's blow. "If you've got the physical evidence, that's what matters; the rest is circumstantial and it's he said, she said," Goldman said. The first part of Pettitte's testimony Tuesday went as expected. He recalled that in a conversation at Clemens' Texas home in 1999 or 2000, Clemens mentioned he had used HGH. Pettitte said he asked Clemens about HGH again in 2005 at an Astros training facility in Kissimmee, Fla. At the time, Congress was holding hearings on steroid abuse in baseball and Pettitte asked the older pitcher what he would say if the media asked him about his use of HGH. Clemens brushed off the question, Pettitte said, and explained that in their previous conversation he had said it was his wife, Debbie, who used HGH. "I was a little flustered because I thought he told me he did," Pettitte said. But during cross-examination Tuesday, Attanasio drew out that the initial comment about HGH was made in passing during a strenuous workout, before throwing the final wrench in the works Wednesday morning. The early problems for the government have reopened the question of whether chasing after sports stars is a worthwhile use of resources. U.S. Atty. Gen. Eric Holder stood by the prosecutors after a question at a news conference Wednesday on an unrelated matter. "The charges there are serious ones," he said. It's about testifying falsely before Congress. On that basis, I think it was a justified use of our resources to bring the case.