During the final week of George W. Bush’s presidency, the Defense Department’s inspector general issued a report exonerating a military public relations program that had drawn fire for trying to manipulate television and radio news coverage. At the time, some members of Congress considered the investigation a “whitewash.” Well, the inspector general’s office now thinks that something really was amiss with its own findings, and it withdrew the report earlier this week. In a move regarded as unusual, Donald M. Horstman, the Pentagon’s deputy inspector general for policy and oversight, issued a memo on Tuesday that said the January 14 report was so riddled with flaws and inaccuracies that none of its conclusions could be relied upon.