Espionage can present profound dilemmas as regards prosecution. In this period, anything told to a jury would be learned by the KGB, at a time when large issues turned on preventing the KGB from knowing what we knew. This dilemma was doubly so when dealing with an Allied government. In October 1949, the British spy Kim Philby arrived in Washington as British intelligence liaison to the U.S. intelligence community. What we observe here is tradecraft of a high order, but also a fairly routine example of organizational behavior.
Secrets are assets to an organization.
It is rare for secrets to be shared with another organization, save as exchange. Almost assuredly not. As best as these events can be reconstructed, it would appear that the Army took a good long look before it decided it could trust the Central Intelligence Agency with secrets about Soviet espionage. The Army may be assumed to have another problem in sharing its secrets. It is entirely reasonable to conjecture that at this time in the United States a good many persons just would not have believed them anyway.