Amid the bipartisan acclaim for former FBI Director Robert Mueller on his appointment as special prosecutor, there has been almost no note of caution. But one comes from Carl Cannon, executive editor of RealClearPolitics, who has established himself as a straight shooter in more than 20 years of covering politics and government.

Writing in the Orange County Register, Cannon reviews the dismal performance of Mueller and James Comey on the 2001 anthrax letter attacks. In the process, Cannon also reviews the New York Times columnist Nicholas Kristof's part in encouraging Mueller's and Comey's focus on an innocent scientist with no experience dealing with anthrax. Cannon credits his former Los Angeles Times colleague David Willman's The Mirage Man: Bruce Ivins, the Anthrax Attacks and America's Rush to War, as the definitive account of the anthrax case.

Cannon is careful to concede the virtues of Mueller, Comey and Kristof. But his column is a reminder that even good people, without apparent political motive, can get important things very wrong. It's something worth keeping in mind as the Mueller investigation plays out.