After Hetherwick's death a plaque was erected in his memory in his home church, the West Church of St Nicholas in Aberdeen. On it he is remembered as, ‘PIONEER MISSIONARY AND EMPIRE BUILDER’. Though he cannot be held responsible for the epithet, he might not have been entirely uncomfortable with it. At the time, Mission and Empire were widely assumed to be very closely related and Hetherwick was an exemplar. Though there was never any doubt that his missionary calling was the primary one, he had also played his part in the building of the Empire. He had campaigned successfully for the establishment of the British Protectorate in Nyasaland, and he had become one of its most prominent civic figures, serving terms on the Legislative Council, being one of the first members of Blantyre Town Council, playing a leading role in the Chamber of Commerce and developing a high profile as an activist and campaigner on a wide range of social, economic and political issues. Admittedly he was a ‘critical friend’ and often a thorn in the side of the British Administration, but he identified strongly with the British Empire, which he viewed as, on the whole, a benign influence.

From the late nineteenth century, it was widely assumed that the Christian missionary enterprise and European colonial rule were close allies, even if there might occasionally be tensions between them. When J. D. McCallum was covering for Hetherwick during his furlough in 1906 he caught the spirit of the times when he gave his assessment of Hetherwick's status: