Confusion of federal prosecutors at court related to Roger Clemens’ case

The desire of the federal government related to the case of Roger Clemens was following: they desired to prove that this sportsman had lied before the Congress about intake of anabolic steroids and HGH. But the government was not able to achieve this goal. It was expected that Andy Pettitte would affirm that Roger Clemens had admitted that he had used the forbidden preparations during a conversation in 1999 or in 2000. But the testimony of Andy Pettitte was shocking for prosecutors. This man stated that he couldn’t confirm that Roger Clemens had used steroids and HGH because he was not sure.
In fact, why were the prosecutors shocked by the affirmation of Andy Pettittte? This person swore for the 2008 Congressional hearings on usage of steroids in the Major League Baseball that Roger Clemens acknowledged that he had administered HGH. But he provided opposite testimony 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 misunderstood Roger Clemens about HGH. Pettitte answered that he is indeed 50-50 about this factor.
When the prosecutors heard the answer of Andy Pettitte, they became confused. They stated that Andy Pettitte never answered this way, when he was asked certain times.
The U. S. District Court Judge Reggie Walton claimed that he understood that Andy Pettitte’s answer has been conflicted. Actually, his statement was following: “I don’t know”.
The attorneys for Roger Clemens used the moment of the federal prosecutors’ embarrassment. They asked the judge to ignore the testimony of Andy Pettitte because he was 50-50. The attorneys claimed that he probably misunderstood the athlete Roger Clemens or he forgot the details of the conversation.  
The government has responded that the jury still allows taking into account the testimony of Andy Pettitte. ASUSA Dunham has confirmed that under federal laws jury is allowed to choose which testimony to believe. This person hopes that the jury will brush aside the testimony which doesn’t support the government.
Thus, the testimony presented by Andy Pettitte and his wife led to problems. Testimonies of Andy’s wife during the first trial led to the declaration of a mistrial by the judge Walton.
Pettitte confirms that he is a friend of Roger Clemens. Clemens must also claim that they are friends after Andy  Pettitte’s last testimony.