A policeman guards a restricted access room hosting a House Intelligence Committee meeting. MLADEN ANTONOV/AFP/Getty Images

A three-time Pulitzer Prize-winning journalist says the House Intelligence Committee made surprisingly erroneous claims in the three-page executive summary of a report that denounces exiled whistleblower Edward Snowden.

The summary asserts that Snowden caused "tremendous damage to national security" and is “a serial exaggerator and fabricator.” The full and unreleased report, 36 pages, was unanimously adopted last week after two years of work, says a committee release.

Barton Gellman, the former Washington Post journalist who first reported some of the most explosive 2013 Snowden revelations about mass surveillance, says two details in the committee summary are demonstrably false and others arguably so.

"A close review of Snowden's official employment records and submissions reveals a pattern of intentional lying," the committee summary says before detailing alleged lies.

The first example offered by lawmakers: "He claimed to have left Army basic training because of broken legs when in fact he washed out because of shin splints."

Gellman writes in an article posted Friday on the Century Foundation's website that the sentence "is verifiably false for anyone who, as the committee asserts it did, performs a 'close review of Snowden’s official employment records.'

"Snowden’s Army paperwork, some of which I have examined, says he met the demanding standards of an 18X Special Forces recruit and mustered into the Army on June 3, 2004. The diagnosis that led to his discharge, on crutches, was bilateral tibial stress fractures."

The second example from the executive summary is a galling mistruth, Gellman writes.

The committee claims about Snowden: "He claimed to have obtained a high school degree equivalent when in fact he never did."

But Gellman writes: "I do not know how the committee could get this one wrong in good faith. According to the official Maryland State Department of Education test report, which I have reviewed, Snowden sat for the high school equivalency test on May 4, 2004. He needed a score of 2250 to pass. He scored 3550. His Diploma No. 269403 was dated June 2, 2004, the same month he would have graduated had he returned to Arundel High School after losing his sophomore year to mononucleosis. In the interim, he took courses at Anne Arundel Community College."

The journalist disputes the accuracy of other assertions, such as Snowden exaggerating his position within the CIA, where he worked before ultimately becoming an NSA contractor, and that he doctored his performance evaluations.

Gellman currently is writing a book about Snowden's disclosures and says he can't yet discuss how he acquired documents about his source's educational and medical history.

"For now, I've clearly staked my reputation on this," he says in an email.

In the meantime, representatives of the U.S. Army and the Maryland State Department of Education tell U.S. News they cannot release documents necessary to replicate the fact-check, citing privacy rules.

Snowden attorneys Ben Wizner of the American Civil Liberties Union and Jesselyn Radack of ExposeFacts.org also were unable to offer the documents.

Jack Langer, communications director of the House intelligence committee, did not directly refute Gellman's claims, but stood by the report in a statement to U.S. News.

“As stated in the report’s executive summary, the information contained in the House Intelligence Committee’s classified Snowden report was gained through extensive inquiries throughout the intelligence community and through interviews with individuals who have knowledge of Snowden’s actions," Langer said. "Although the Committee cannot release further information at this time due to classification rules, the Committee expects more details will become available when a declassified version of the report is published. The report will be submitted to the intelligence community soon for a declassification review and is expected to be published once the review is complete.”

The House and Senate intelligence committees oversee programs conducted by the NSA and other spy agencies affected by Snowden's disclosures. They secretly approve spy agency funding and their members are generally viewed as more deferential to the agencies than rank-and-file lawmakers, many of whom said they were alarmed to first learn of surveillance programs from Snowden.

After unanimously adopting the report on Thursday, the committee members also sent President Barack Obama a letter asking that he not pardon Snowden, who since 2013 has been living in Russia, where he was stranded en route to Latin America when the U.S. State Department canceled his passport.

Snowden "perpetrated the largest and most damaging public disclosure of classified information in our nation's history," the committee members wrote.

The committee action came as the ACLU and other groups clamor for a pardon from Obama, who despite being badly embarrassed by the leaks ultimately signed into law the mass surveillance-curtailing USA Freedom Act, which ended the automatic bulk collection of domestic call records. The Post, despite sharing a Pulitzer Prize with the Guardian for reporting on Snowden's leaks, opposes clemency.

The Post's editorial board, in calling for the prosecution of its source, leans in part on the committee's judgment, saying: "[Snowden's] revelations about the [NSA's] international operations disrupted lawful intelligence-gathering, causing possibly 'tremendous damage' to national security, according to a unanimous, bipartisan report by the House Permanent Select Committee on Intelligence. What higher cause did that serve?"

Gellman believes Snowden did more good than harm and says, "to be clear, I think all this debate about shin splints and GED is a silly diversion (trifling, I wrote), but I couldn't resist the irony of lying about the evidence of lying."