Recent experiments resolved nucleation and growth of graphite during solidification of ductile cast iron in 3D and time using synchrotron X-ray tomography [1]. We use the experimental observations to analyse the relation between graphite growth rate and the state of the particle neighbourhood to pinpoint possible links between growth rate of individual graphite spheres and the overall solidification state. With this insight we revisit existing models for growth of spheroidal graphite and discuss possible modifications in order to describe the critical final stage of solidification correctly.