In their article, Inanaga et al. have presented an angular distribution for the desorption of hydrogen molecules induced by hydrogen atoms impinging on a hydrogenated Si(100) surface and compared the measurement with classical trajectory calculations based on a method developed previously by Kratzer. This paper deserves two comments. First, we note that the calculated angular distribution shown in the paper by Inanaga et al. is not reproducible using their potential and set of parameters. Secondly, Inanaga et al. give the incorrect impression that classical trajectories calculated by themselves and by Kratzer would support the hot-complex mechanism. In the following, we address these two issues.