Coombe was a made a knight during a visit to England in June 1924, "in recognition of his public services". However, in 1931, he was prosecuted and found guilty of income tax evasion, and fined £100. After Union Cinemas collapsed the same year, Coombe was forced to sell much of his property, although his sons remained in the cinema business. He later moved to Glenelg, a suburb of Adelaide, and then to Surrey in England, where he died in 1959.