(CBS News) What a difference a day makes at the Roger Clemens perjury trial.
Former teammate Andy Pettitte, who testified that the legendary pitcher admitted using human growth hormone, now says he may have misunderstood. This is what Clemens has been saying all along.
Pettitte was asked by Clemens' attorney how sure he was about his testimony the previous day that Clemens once told him he used performance enhancing drugs.
The attorney asked if it would be fair to say it was "50-50?"
Pettitte replied, "I'd say that's fair."
This is the government's second attempt at trying to prove that Clemens lied under oath when he told Congress in 2008 that he never used performance enhancing drugs.
Pettitte's testimony is especially damaging to the government because he was considered the stronger of the their two key witnesses. The other, Clemens' former trainer Brian McNamee is expected to testify as early as next week that he injected Clemens with steroids and HGH. But his credibility is in question.