We have applied the non-adiabatic phase matrix method for vibrational scattering processes to a system which supports an extremely broad (short-lived) shape resonance. This method provides a unified, systematic treatment of the range of physical effects that influence the collision as the nuclear geometry varies, from strongly resonant to purely background scattering. For this implementation we have chosen the prototypical shape resonance in scattering below 10 eV. We compare vibrational cross sections and from the present non-adiabatic theory to results from fully converged body-frame vibrational close-coupling calculations and from purely adiabatic studies using the energy modified approximation.