Why was Obama kept in the dark about Petraeus's affair?

Such prudence is a well-established approach, the law enforcement official says. “This has been long standing practice for many, many years.” The official cited a 2007 memo by then Attorney General Michael Mukasey regarding contacts with the White House during criminal investigations. As part of the process of cleaning up the politically motivated firing of U.S. Attorneys under his predecessor, Alberto Gonzales, Mukasey issued explicit instructions that Justice officials had to follow. “Alerting the White House of an ongoing investigation? That’s a huge no-no,” the law enforcement official says.

Unfortunately for the Obama team, there are huge holes in their arguments. For starters, Mukasey himself says there is no prohibition on Justice-to-White House communication in criminal investigations. “The memo makes it quite clear that not only is that not the case, it is explicitly not the case,” Mukasey told TIME Tuesday evening. Says Mukasey: “The point is not that the White House can never be apprised of a pending criminal investigation; the point is that the White House should not reach out and influence a pending criminal investigation.”

More to the point, Mukasey’s memo specifically instructs “all components of the Justice Department” that “it is critically important to have frequent and expeditious communications relating to national security matters, including counter-terrorism and counter-espionage issues.” If anything, the Mukasey memo orders Justice Department officials–including prosecutors and the FBI–to communicate with relevant political authorities when they make a discovery like they did in the Petraeus case.

The Mukasey memo isn’t binding on the current Attorney General, or the Justice Department. But it is not the only precedent that suggests the Administration handled the Petraeus affair badly.