A spin-dimer analysis of the anisotropic spin-exchange interactions in the distorted wolframite-type oxides CuWO4, CuMoO4-III, and Cu(Mo0.25W0.75)O-4 was performed by Koo and Whangbo (Inorg. Chem. 2001, 40, 2161-2169). For Cu(Mo0.25W0.75)O-4, a magnetic structure with a magnetic unit cell doubled along the a and b axes has been predicted, but neutron powder diffraction on Cu(Mo0.25W0.75)O-4 did not confirm such a magnetic structure. In the present work, a detailed spin-dimer analysis, considering the influence of particular atomic structure parameters, finally revealed that a wrong coordinate transformation of the Cu z coordinate of the Cu(Mo0.25W0.75)O-4 structure is responsible for the prediction of the new, hypothetical magnetic structure. The deviation from the correct value is too small to be recognized by unreasonable bond lengths or angles but is sufficient to change one specific calculated value that is responsible for the prediction of the hypothetical magnetic structure.