Born in Victoria, Emslie "Buck" Yeo's major's accomplishments were in coaching and refereeing in Vancouver after he had attended McGill University. He taught, coached and refereed rugby and basketball at King Edward High School before becoming a senior referee. From the time he began officiating McKechnie Cup matches in the early 1920's until he did his final games in 1939 his overall record was without parallel. When he was not carrying the whistle he was a touch judge.
He served as the Chairman of Referees for both the Vancouver and British Columbia Rugby Unions as well as officiating matches against New Zealand All Blacks, in both 1925 and
1936, New Zealand Maori, New South Wales Waratahs and Japan. In 1936, the All Blacks requested that he be the referee.
The World Cup matches between UBC and an American university benefited from Buck's officiating as did the New Zealand Shield school matches for which he did every match but one from 1925-1938.
In the book First Fifty Years: Vancouver High Schools 1890-1940, it is stated that "Mr. Yeo, himself an old rugby player, brought a wealth of knowledge and enthusiasm to the coaching of many of King Edward's rugby and basketball team, and came to be regarded as the dean of rugby referees of Vancouver." He took a sabbatical from teaching during the Second World War and ended his career as principal of Magee Secondary School.