In a recent paper, Keen and Lovesey (KL) (2003 J. Phys.: Condens. Matter 15 4937) presented a theoretical model to account for lines of intensity, in addition to Bragg peaks, observed by Fillaux, Cousson and Keen (FCK) (2003 Phys. Rev. B 67 054301 and 2003 Phys. Rev. B 67 189901 (erratum)) in single-crystal neutron diffraction measurements on potassium hydrogen carbonate (KHCO3). In this comment it is demonstrated that KL's model is irrelevant and cannot account for the data under consideration.