Carlson was a close friend, and possible lover, of Vladimir Fabry, a Slovak political refugee and U.S. legal adviser to the United Nations in the Congo, who died on 18 September 1961, in the same plane crash that killed also Swedish diplomat and the second Secretary-General of the United Nations Dag Hammarskjöld in Northern Rhodesia (1961 Ndola United Nations DC-6 crash). Fabry first met in 1949 at Geneva after he had succeeded in having his father Peter Palka released from a concentration camp.