At the end of the day-or at least four-plus hours that felt like a day-the most important person in the room for the congressional hearing on steroids in baseball yesterday wasn’t even in the room.

That, of course, was Andy Pettitte, the close friend and teammate of Roger Clemens with both the New York Yankees and Houston Astros. And Pettitte was about the only thing that Clemens, his accuser Brian McNamee, a former strength and conditioning coach for both men, and the congressional panel could all agree upon: they all believe he is a good and honorable man. (Apparently, Pettitte’s prompt confession that he cheated by taking human growth hormone trumps his having cheated in the first place.) After a maze of contradictions between Clemens and his former personal trainer, Maryland Rep. Elijah Cummings reduced the he said/he said imbroglio to the simplest of equations: “The person I believe the most is Mr. Pettitte.”

The Committee on Oversight and Government reform was apparently so impressed with Pettitte’s anguished cooperation in his earlier deposition that it spared him having to repeat it publicly yesterday-and, most of all, having to look his pal in the eyes as he contradicted Clemens’ tale. Pettitte’s own is a simple story, as revealed by committee chair Henry Waxman; it’s a rather damning one, when it comes to his buddy. Having previously admitted that McNamee had been telling the truth about injecting him with HGH, Pettitte, according to Waxman, told the committee staff that Clemens had discussed taking HGH with him back in 1999 or 2000. He was so shocked by the revelation that he told his wife, who confirmed that in her own deposition to the committee.

As a result, after a day in which Clemens was truly dynamic-he mustered both anger and outrage, flaunted his patriotism and even locked horns with committee chair Henry Waxman, interrupting the congressman’s final summation for one last pitch of his own-he was left with the feeblest of defenses to Pettitte’s sworn testimony: that his buddy must have “misheard” him. And, in Clemens’ view, that initial misunderstanding was compounded by another “misremembered” conversation between the pitching pals in 2005. None of these contradictions may be enough to sustain a perjury conviction against Clemens in a court of law-even though it is certain that at least one of yesterday’s two key witnesses is lying. But it was enough to lead Rep. Cummings to say that while he counted Clemens as one of his sports heroes, “It’s hard to believe you.”

Not that McNamee didn’t get roughed up during the hearing. But we didn’t really learn anything new. We already knew he was a puffed up phony with a meaningless PhD from a diploma factory, a sycophant who willingly broke the law for his clients and a man who in the past lied about a host of matters-to the press and, more importantly, to law enforcement. In other words, a pretty typical witness in a criminal matter. Liars and lawbreakers are particularly useful because there are no Mother Theresas shooting players in the butt with steroids and HGH. Given the liars that have paraded before congressional committees, some of them top government official dissembling about critical matters of state, the bewilderment and anger with which some members-notably, Indiana’s Dan Burton-greeted McNamee was surprising.

Perhaps that level of outrage would have been better trained on Clemens’ pronouncements that he is “a trusting person” and “a forgiving person.” He mentioned his level of trust in an attempt to explain how he could let McNamee inject him with anything--even the legal substances Clemens claims were in those needles. He mentioned his forgiveness to explain why he kept working with McNamee even after he learned that, without his knowledge, the trainer had injected Clemens’ wife with HGH. I am positive that “trusting” and “forgiving” are adjectives that have never before been used to describe Clemens, a tough, circumspect man with a well-earned reputation for harboring grudges.

Then again you know Clemens is a wee bit desperate when he’s counting on an affidavit from Jose Canseco, a man who has built his post-baseball career on a love affair with steroids and who was recently accused of offering to keep a player’s name out of his next tell-all book in return for money. (Canseco has denied that allegation.) Then there was the bizarre tale of the Clemens family’s former nanny, who might also have been able to confirm Roger’s account that he hadn’t attended a certain party at Canseco’s home. With the committee trying to locate her, Clemens found her first-and invited her to his home for a reunion, helping out by urging her to be truthful and by reminding her that he had skipped that Canseco bash.

At times like this, I hark back to the wit and wisdom of the late Boston sportswriter Will McDonough, perhaps the only person in our trade who was anywhere near as tough as Clemens and one who rivaled him when it came to bearing grudges. Not surprisingly, the two men weren’t big fans of one another. McDonough labeled Clemens “the Texas con man” at a time when he was at the height of his popularity here in Boston. And despite Clemens’ stature in the game and the city, the harsh nickname kind of stuck. If McDonough could have witnessed today’s sparring, I know that about the only thing he would have believed coming out of Clemens’ mouth was that he had no idea what a vegan is.