Probably not. The Supreme Court in several cases, has upheld the right of Federal employees to communicate information and to do so anonymously.

"...absent a specific legal prohibition, government employees have a constitutional right to speak out on matters of public concern. This right was recognized by the Supreme Court in 1968 and is unchallenged today."

In this case, nobody has pointed to a legal prohibition preventing a former government employee from passing on his personal notes of a meeting that was not under the restriction of National Security to a third party.