In the framework of the isobar doorway model nonstatic terms are introduced into the effective πN∆ transition opertor through the transformation from the πN to the π-nucleus CM-system. The effect of these recoil corrections to elastic and inelastic π-12C scattering in the ∆ (33) energy range is shown to be important for the position miniam and the structure of the differential cross sections at large angles.It is a pleasure to thank Prof. Dr. M.G. Huber for critical and helpful discussion on this manuscript. We would also like to thank Drs. J.P. Egger and J. Piffaretti for providing us with their data before publication.