[O I] λλ 6300,6364, [O II] λλ 7320,7330, and [O III] λλ 4959,5007 line profiles at t_max+565.0 days. The velocity scale is centred on the blue doublet component in the left panel and on the red component in the right panel. [O II] and [O III] only reach out to approximately the velocity of the CSM shell (v_CSM), much less than the photospheric velocity (v_FeII) and the maximum velocity of the ejecta (v_max). In contrast to that, the [O I] profile extends to ⊈ 12 500 km s⁻¹. This points to [O II] and [O III] being produced close to the CSM shell whereas [O I] is produced in the SN ejecta.