In previous experiments, a nearly complete vibrational spectrum of the CS2 molecule in the Sigma(g)(+) state has been obtained using a laser induced fluorescence method. The statistical tests of the random matrix theory, applied on this spectrum, suggest a transition to quantum chaos. The aim of this letter is to show that these statistical results are biased because of a nonsingle excitation of the molecule. This is experimentally confirmed by high-resolution new experiments in supersonic jet, using the powerful laser chain of the french project for the isotopic separation of uranium by laser (SILVA project).