Roger Clemens' perjury trial was moving rather slowly before Wednesday, when Andy Pettitte's testimony shocked the prosecution and changed the entire complexity of the trial.

Pettitte's claim that Clemens admitted to him over a decade ago that he used human growth hormone is not as clear-cut as it once was, since Pettitte agreed on Wednesday there is a "50-50 chance" he misunderstood Clemens 12 years ago. Clemens' attorney Michael Attanasio cross-examined Pettitte, during which the former teammates reportedly did not make eye contact.

With their case seeming to fall into pieces, the insult to injury was when U.S. District Judge Reggie Walton indicated that he was seriously considering an argument from Clemens legal team that could force the jury to eliminate any consideration of Pettitte's original testimony that Clemens admitted to him that he had used HGH.

"What we do have is an indication that maybe he did mishear him," Walton said with jurors out of the courtroom.

Walton could rule on Pettitte's testimony as early as Thursday.This would leave the prosecution's case relying on the credibility of former trainer Brian McNamee, which is almost as good as not having a case at all.

McNamee filed a motion to kill a subpoena served by the defense on his estranged wife for records from their divorce proceedings a couple of years ago. The defense is looking for these records to further attack his already shattered credibility. There was no indication, however, when the judge would rule on the request made by McNamee.

The only light at the end of this tunnel for the prosecution is the testimony of FDA agent Jeff Novitzky, who has led doping investigations since 2002 and was at the forefront of the BALCO investigations which eventually led into investigations of McNamee.

According to Novitzky's testimony, Clemens' name came up in discussions with McNamee on his PED distribution. But again, that strength of that testimony depends on McNamee's credibility, since only he and Pettitte are really the only sources here.

For denying he ever used performance-enhancing drugs in his Feb. '08 deposition and then his appearance before the House Committee on Oversight and Government Reform, Clemens is facing six federal charges of perjury, giving false statements and obstruction of Congress.

The trial, which is likely to take two more trial weeks, resumes at 11 a.m. on Thursday, two hours later than the usual starting time.

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