He was later a coach for the Canadian Winnipeg Falcons that won the first ever gold medal in Ice hockey at the 1920 Summer Olympics.

[5] After studying sports training and therapy in England, Guðmundur moved to Winnipeg in Canada in 1914 where he learned Greco-Roman wrestling and Ice hockey.

[7] In 1920, he was the trainer of the Winnipeg Falcons when it won the gold medal in ice hockey for Canada at the 1920 Summer Olympics.

Steindór later withdrew the charges, claiming that bootleggers had paid him to implicate Guðmundur to those crimes as he was hurting their business.

[8] Guðmundur was acquitted of ill treatment of patients but was sentenced to eight months in prison for having sexual relations with another man.