Unfortunately I can't get the link to the Washington Post article to function correctly, but found the cite at http://www.iraqnow.blogspot.com. Good commentary on the findings; especially interesting that the mortality of Lieutenants is 19% higher than the rest of the force combined. Looks like the junior officers are indeed doing their jobs.
The most interesting statistic: Lieutenants have the highest mortality of any rank, 19 percent higher than the rest of the Army combined. It doesn't surprise me. America, once they climb that initial and steep learning curve, your lieutenants are doing yeoman's work. More than any other rank, it falls to the lieutenant to say "follow me."