In a previous experiment on VESUVIO (RB 1520359) we aimed at investigating para-iodo-benzoic acid (IBA), in particular the onset in temperature for the appearance of the hydrogen disorder in the crystal as compared to the parent compound benzoic acid (BA). The nature of the disordered positions of the hydrogen atoms in substituted crystalline benzoic acids is a long standing debate. The disorder in the main compound, benzoic acid (BA), has been investigated with many different techniques ranging from crystallography to vibrational spectroscopy and interpretations are ranging from chemical tautomerism to quantum condensation. Our NCS results show also that the origin of the disorder is due to thermally activated stochastic proton jumps across the hydrogen bond. To reinforce this hypothesis, we propose to measure a partially deuterated BA.