Clausen, a lawyer and a former Assistant United States Attorney from San Francisco, and a "civilian at heart" had joined up "for the duration" of the war, being discharged in August 1945.
He appeared before the Congressional Hearing, and was asked to show Congressman Murphy his Summary exhibit of Far Eastern documents, as Congressmen Ferguson and Gearhart who were in the "Kimmel camp" had held onto the two copies sent to the Committee to prevent other members seeing them.
[1] Stimson got the Army Pearl Harbor Board report (actually two reports, with a second Top Secret section on codebreaking) on Pearl Harbor with its criticism of General George Marshall and Secretary of State Cordell Hull, but "fatally flawed" from crucial but withheld evidence and perjured testimony.
After discussing the Board report(s) with General Cramer (the Judge Advocate General) and with Major (later Lt. Col) Clausen (who had been Assistant Recorder to the Army Board), Stimson appointed Clausen as his Special Investigator to retake evidence and follow unexplored leads.
Colonel Dusenbury, of the US Army SIS, testified that he received the fourteenth part (which said diplomatic relations would be broken) from the Navy (OP-20-G) about midnight (Washington time).
Marshall got assurances that the final warning on December 7 would be received by everyone before 1 pm Washington time; he had to send Colonels Bratton and Bundy back to the message center twice to get this confirmation.
And Roosevelt, for often vacillating, and for making a number of telephone calls after reading the Japanese message, but not one to Marshall.
He was also responsible for distributing MAGIC information to the President; though unlike the Army (with Dusenbury and Bratton) he had no relief officer.