Federal government couldn’t prove that Roger Clemens had lied before Congress about usage of steroids and HGH

The desire of the federal government related to the case of Roger Clemens was following: they wanted to prove that this sportsperson had lied before the Congress about administration of anabolic steroids and HGH. But the government couldn’t do it. It was expected that Andy Pettitte would say that Roger Clemens had told him that he had applied the banned medications during a conversation in 1999 or in 2000. But the affirmation of Andy Pettitee was shocking for prosecutors. He said that he couldn’t confirm that Roger Clemens had used steroids and HGH because he was not sure.
Actually, did the statement of Andy Pettitte shock the prosecutors? This person swore for the 2008 Congressional hearings on application of steroids in the Major League Baseball that Roger Clemens acknowledged that he had used HGH. But he pronounced opposite statements at the Barrett Prettyman Federal Courthouse in Washington.
Michael Attanasio, a defense attorney for Roger Clemens, asked Andy Pettitte whether he may claim that he is 50-50 that he has understood wrongly Roger Clemens about HGH. Andy Pettitte answered that he is indeed 50-50 about this aspect.
When the prosecutors heard Pettitte’s answer, they became confused. They stated that Andy Pettitte never said this way, when he was asked certain times.
The judge Reggie Walton noticed that he understood that Andy Pettitte’s answer has been conflicted. Actually, his testimony was following: “I don’t know”.
The attorneys for Roger Clemens utilized the moment of the prosecutors’ confusion. They asked the judge to brush aside the testimony of Andy Pettitte because he was 50-50. The attorneys concluded that he probably misunderstood the athlete Roger Clemens or he forgot the details of the conversation.  
The government has noted that the jury still allows taking into account the testimony of Andy Pettitte. ASUSA Dunham has claimed that under federal rules jury is allowed to choose which affirmation to believe. He hopes that the jury will brush aside the testimony that doesn’t support the government.
So, the testimony provided by Andy Pettitte and his wife led to problems. Testimonies of Andy’s wife during the first trial resulted in the declaration of a mistrial by the judge Walton.
Pettitte affirms that he is a friend of Roger Clemens. Clemens must also confirm that they are friends after Andy  Pettitte’s last testimony.