Note: These comments refer to a Wikipedia entry as it was in 2013
It is stated here that, after Golitsyn defected in December 1961, he was interviewed by CIA CI Staff chief James Angleton. Actually, as a Soviet KGB officer, he came organizationally under the jurisdiction of the Soviet Bloc Division, which would be responsible for handling and interviews, which certainly included an early interview by Angleton or one of his staff. The statement here that he provided significant information on Philby, Burgess, and Maclean, Vassall, and Kopatskiy is not supported by the record, and he definitely did not confirm Philby's guilt. His information on Vassall, like most of his reporting, was vague and inaccurate, and his report that KGB agent Vassall was high-ranking in the British Admiralty administration prevented Ml5 from exposing him until Yuriy Nosenko provided specific details on his identity. Kopatskiy was known to Golitsyn only as "Sasha", a supposedly major KGB penetration of CIA, and it took several months to determine that "Sasha" was Kopatskiy, who had worked for CIA in Berlin under contract for several years, but was fired by CIA several months before Golitsyn defected.
Angleton's identification of Goiitsyn as "the most valuable defector ever to reach the West" is a total and absolute contradiction of the truth. Exactly the opposite is true. Goiitsyn identified not a single significant KGB asset at all in the West, his exaggerated and vague leads to Vassall and Kopatskiy being his best contribution. A French official in NATO was arrested following his equally vague reporting of that KGB penetration, but the French official had not worked for the government until two years after Golitsyn defected! His accusation against a Canadian ambassador was not confirmed because he died of a heart attack while being interrogated; Golitsyn may have been right in that case, but nothing came of it.
The real tragedy is that Angleton, as the generally recognized leader of Western counterintelligence for 20 years, was demonstrably as much of a failure in identifying KGB penetrations and false defectors as Golitsyn was. There is not one significant case or officer of CIA or other Western governments which Angleton identified as under KGB control that turned out to have been evaluated correctly by him. To a large extent, this was the result of his absolute faith in Golitsyn and Golitsyn's modus operandi, in spite of the fact that Golitsyn had been medically diagnosed as paranoid. The devastating consequences of Angleton's/Golitsyn's false accusations against CIA's Soviet assets, defectors, and even staff officers, were a shocking loss of intelligence, and near paralysis of CIA operations against the USSR at the height of the Cold War. The statement here that Angleton was dismissed from CIA for this (and other actions) is wrong. DCI Colby offered him a different assignment, but he turned it down, and stayed on for another nine months after being removed from the CI Staff.
Golitsyn's accusations against UK Prime Minister Wilson and Finnish President Kekkonen, and the theory that the KGB poisoned UK Labour Party leader Hugh Gaitskell are typical of the paranoid thinking of Golitsyn which was ultimately never supported by any facts, but accepted by Angleton, as well as MIS officer Peter Wright ("Spycatcher").
The CIA mishandling of KGB defector Yuriy Nosenko is directly attributable to Angleton/Golitsyn. After the first case officer who met him when he walked in in Geneva in June 1962, Tennent ("Pete") Bagley, came to report the event to Angleton as "the most important operation CIA has ever had”, Angleton convinced him that Nosenko was actually under KGB control (Golitsyn's evaluation). The description here of Nosenko's subsequent handling after he defected in February 1964 is not quite accurate, but generally portrays the truth.
The false evaluation and mishandling of Nosenko eliminated acceptance of his reporting on the Soviet relationship with Lee Harvey Oswald, which would have been a crucial element in assessment of possible Soviet involvement in the assassination of President Kennedy. The FBI did not agree with the CIA evaluation of Nosenko as under KGB control, but had little information to go on until Nosenko was released from solitary confinement in late 1968 and declared bona fide by CIA in 1969. Contrary to the insinuation here, although Helms chaired the meeting which found Nosenko bona fide, he continued to comment, even after his retirement. that he had never made up his mind about Nosenko.
https://en.wikipedia.org/wiki/Anatoliy_Golitsyn