Yesterday, the Roger Clemens cheating scandal got wider without getting deeper. Following his Sunday night appearance on “60 Minutes,” in which he asserted that his former trainer Brian McNamee injected him with vitamin B-12 and the painkiller lidocaine, not steroids or human growth hormone, the pitcher filed a defamation suit against his accuser. At a subsequent press conference, Clemens played a 17-minute taped conversation between McNamee and himself that was recorded last Friday in which Clemens denied using steroids and McNamee never said that Clemens did — but he never said that he didn’t either.

The phone call seemed to be more about posturing than a serious attempt at a resolution. McNamee told Clemens that his son was dying. Clemens sympathized, but the conversation soon turned to the current controversy. Clemens never directly called McNamee a liar, except by implication, saying, “I just don’t know why you did it.” When McNamee told Clemens that he was sorry that Clemens’s family was suffering due to the story and that he would do whatever he could to help, Clemens responded, “You just need to come out and tell the truth, I didn’t do it, all this stuff.”

RELATED: Excerpts of Clemens-McNamee Phone Conversation

In perhaps the most telling exchange, an anguished McNamee offered up a reason why he might have lied, if indeed he did lie. After Clemens said, “For the life of me I’m trying to find out why you would tell guys that I used steroids,” McNamee shouted, “Roger, tell me what the [expletive] you want me to do. My son is dying. He’s 10!” It sounds like an old-fashioned Hollywood story: Choose between your best friend and staying out of jail so you can help your child. Every parent knows what the choice would be.

However, the lawsuit, as well as Clemens’s declaration that he would go to Washington and testify under oath before Congress, were the most significant developments of the day. In both instances, Clemens will potentially put his freedom on the line by opening himself to charges of perjury if he is found to have lied in denying McNamee’s charges. In addition, fighting a protracted legal battle is expensive, and, as Clemens suggested to Mike Wallace, even a fortune as vast as the one that Clemens has made from baseball can be exhausted in such a pursuit.

What stands out most of all in the Clemens-McNamee case is how in the absence of corroborating evidence, the ultimate truth is unknowable. Both of the combatants have incentive to lie: McNamee to stay out of jail and Clemens to save his reputation. Both are in the kind of peril that would cause even a highly moral person to forsake his or her scruples. And as Clemens and his attorneys will repeatedly point out for however long this matter drags on, there are reasons to believe that McNamee is not a highly moral person, starting with his 2000 article in the New York Times claiming that suspicions of steroid use by major leaguers was “unsubstantiated and unfounded.”

This entire situation was avoidable had the Mitchell investigation not been a complete failure and its resultant report not an ethical nightmare. Having failed to uncover significant wrongdoing, Mitchell and his henchmen seized on the testimony of McNamee and former Mets factotum Kirk Radomski to make up the substance of the report. This was in and of itself a questionable decision given the sheer number of names that Radomski, in particular, gave up. This small, unimportant figure, employed by just one team, with only David Segui as his proselytizer, managed to compromise a large pool of players. Yet, it defies all logic to conclude that Radomski was the only such enabler in baseball and Segui the only such acolyte. There are 29 other teams, each with a diverse group of players, some of which would have the desire or the incentive to cheat. Those players and their syringe-wielding accomplices escaped Mitchell’s scrutiny, creating an uneven justice in which a handful of players were forced to go up against the wall in lieu of all those who Mitchell couldn’t find.

Sure, you can say, “So what? They still cheated. They still deserved punishment,” and this may be true. Still, a more responsible investigation would not have presented only a tip and let it suffice for the whole iceberg. Mitchell quit with the job not even half-finished.

The abortive nature of the report is what put Clemens, McNamee, Hall of Fame voters, and the larger population of baseball fans in an impossible bind. A different prosecutor, having failed to advance the case against Clemens beyond the word of one highly leveraged witness might have stamped a big “to be continued” on that part of the investigation and begged for more time, or failing that, let it drop altogether. It’s understandable on a human level that Mitchell and his cohorts were reluctant to cut bait on Clemens; without him, their report would have been lacking in a new, killer disclosure of a marquee name. After all, the allegations against Barry Bonds had been out of the bag long enough to be the subject of a book or three, and in the grand scheme of things, who the heck are Miguel Tejada and Andy Pettitte compared to the Rocket, a first-ballot Hall of Famer? They are just players, often good ones, but not the demigod, the modern Walter Johnson, that Clemens is.

Yet, Mitchell, if he was truly to be an impartial investigator (which, as my colleague Tim Marchman convincingly argued here in The New York Sun back on December 14 is something of a bad joke), if he was to be in the end, simply a human being, he had a responsibility not just to his masters at Major League Baseball, but to the players who he must have known would be destroyed by what he said. The case should have been open-and-shut, or it should not have been presented at all.

The possibility exists that Clemens will now climb onto one of many witness stands and self-immolate, like some macho mirror image of Oscar Wilde in the dock. Yet, if it does come to pass that McNamee’s attorneys are able to refute Clemens’ testimony convincingly through solid, factual evidence, it wouldn’t alter the truth of Mitchell’s ineptitude.

Mr. Goldman writes the Pinstriped Bible for yesnetwork.com and is the author of “Forging Genius,” a biography of Casey Stengel.