Simon Brown
Simon Brown was a civil servant in London, 1949. He had a wife and a son.
He was a man of routine, leaving his office and a set time and returning home soon after. In July 1949, he met Amanda, and began having an affair with her. His wife noticed the change in routine - that he went to Bloomsbury after work to meet her on a Tuesday and Thursday - and hired Honoré Lechasseur to look into his activities.
During his time with Amanda, the two of them had a mutual interest in politics and they talked about the state of the world. After she learned that Simon worked on deciphering the atomic bomb's secrets for the British atomic weapons programme, their conversations of politics merged with that subject. They came to the mutual agreement that for the betterment of humanity, everyone should know the secrets of atomic weapons. Simon spread his knowledge to the world, and in retaliation, Joseph Stalin released his atomic bombs on the planet, and the Party took over.
Radford placed his actions as the sole factor for the creation of a new timeline. (PROSE: The Winning Side)