Accuracy In Media wonders how NBC can allow Tim Russert to cover the Libby case and, in effect, opine on his own credibility as a witness.
I'm guessing that ratings has something to do with it. It's certainly not because NBC wants its reporters to explain their role in this.
Although having said that, if the alternative is explanations such as the one Andrea Mitchell attempted with Don Imus, silence is the better part of valor. Or something.