In December, I was asked to file a second report on an automobile accident that took place back in September, during a visit to Los Angeles. A truck slammed into my car from behind while I was stopped at a traffic light.

As I sat down to write a new report, I tried to recall the details, beginning with where the accident took place, which I remembered as having been on Wilshire Boulevard.

Fortunately, I had saved a copy of my first report on this same accident, which showed that it took place on Santa Monica Boulevard, not Wilshire, which was the street up ahead.

What if I had not saved a copy of that first report, and had written down and signed a report saying that the accident took place on Wilshire Boulevard, when everyone else involved said it was on Santa Monica Boulevard? If this was a statement made under oath, I could have been prosecuted for perjury.

All this made me think back to a more important case where memories differed and a man's life was ruined because of a perjury conviction. Moreover, it was about something that was no more crucial than the name of the street where an accident took place.

That man was Lewis ("Scooter") Libby, assistant to Vice-President Dick Cheney. He testified under oath that he had not leaked to reporters the information that Valerie Plame worked for the CIA, but had in fact learned about it himself from reporters, including Tim Russert.

Unfortunately for Scooter Libby, there was testimony from Tim Russert that he himself did not know that Valerie Plame worked for the CIA at the time of his conversation with Libby. Perhaps even more damaging, the White House's own press secretary, Ari Fleischer, said that Libby mentioned to him that Ms. Plame worked for the CIA. This was a few days before Libby talked with Russert.

It seems clear that Libby had his facts wrong.

But in more than 8 months between the various conversations at issue and Scooter Libby's testimony before a grand jury, those facts assumed a far greater importance than they had at the time, when there was no reason for them to be particularly memorable.

While it is a crime to reveal the identity of an undercover CIA agent, Valerie Plame was no longer an undercover agent, her identity having already been revealed long before this whole episode. She was now just someone with a desk job at CIA headquarters in Virginia when this furor broke out. Continued...