Penatagon Denies Records on Allen-Kelley Investigation

The Penatagon has denied the Washington Post's request for details on the investigation of Gen. John Allen and his emails with Tampa Socialite Jill Kelley because releasing any of the records would violate the personal privacy of third parties.

While I'm not sure that this decision is wrong, I'd like to know if the DOD actually balanced the public interest in the records against the privacy interests of the parties involved.  How a civilian, Kelley, got access to military leaders and installations seems like a public interest that would, even if no misconduct is found, would lead to the release of some of the records.