In a recent paper by Blostein et al. (Physica B 304 (2001) 357) was presented a critical theoretical analysis of different procedures, with which data of deep inelastic neutron scattering (DINS) experiments are usually processed. One part of that criticism—which is experimentally tested in the present paper—claimed the existence of serious errors in the determined areas of overlapping DINS-peaks, in particular in the case of the considerable overlapping of the strong proton peak with the weak deuteron peak. Our experimental test presented here consists in the comparison of the D-peak areas determined from DINS-data of H/D mixed systems, taken in both the “forward” and the “backward” scattering directions. Since there is no H-peak in the “backward” scattering direction, the claimed error cannot occur in this regime. New experimental results from (A) pure D 2O, and (B) the equimolar H 2O/D 2O mixture, are presented. The liquids were contained in a Nb can. For both systems, it is shown that the D-peak areas in the “forward” and the “backward” scattering directions are essentially equal. This proves that the aforementioned criticism, although very stimulating, is of no relevance in the specific context of our (previous and present) DINS experiments. Moreover, the new experiments show that the cross-section of D is fully consistent with conventional expectations.