Last week, the network aired a feature where an expert examined documents purportedly showing Bush disobeyed a direct order to undergo a physical during his service in the Texas Air National Guard.
Marcel Matley, who examined the signature on the documents told the Washington Post there was "no way" he could authenticate the documents themselves since they were copies "far removed" from the originals.
A detailed comparison by the Post of memos obtained by CBS News with authenticated documents on Bush's National Guard service reveals dozens of inconsistencies, ranging from conflicting military terminology to different word-processing techniques.
Citing confidentiality issues, CBS News declined to reveal the source of the disputed documents, which they have had for more than a month, or to explain how they came to light after more than three decades.
The White House commented on the accusations for the first time Monday, denying the president defied a direct order, the Washington Times reported.