Duality of (2,3,5)-distributions and Lagrangian cone structures

As was shown by a part of the authors, for a given $(2,3,5)$-distribution $D$ on a $5$-dimensional manifold $Y$, there is, locally, a Lagrangian cone structure $C$ on another $5$-dimensional manifold $X$ which consists of abnormal or singular paths of $(Y,D)$. We give a characterization of the class of Lagrangian cone structures corresponding to $(2,3,5)$-distributions. Thus we complete the duality between $(2,3,5)$-distributions and Lagrangian cone structures via pseudo-product structures of type $G_2$. A local example of non-flat perturbations of the global model of flat Lagrangian cone structure which corresponds to $(2,3,5)$-distributions is given.