In this paper we evaluate sources of background for the γp→ωp, with the ω detected through its π0γ decay channel, to compare with the experiment carried out at ELSA. We find background from γp→π0π0p followed by decay of a π0 into two γ, recombining one π0 and one γ, and from the γp→π0ηp reaction with subsequent decay of the η into two photons. This background accounts for the data at π0γ invariant masses beyond 700 MeV, but strength is missing at lower invariant masses which was attributed to photon misidentification events, which we simulate to get a good reproduction of the experimental background. Once this is done, we perform an event mixing simulation to reproduce the calculated background and we find that the method provides a good description of the background at low π0γ invariant masses but fakes the background at high invariant masses, making background events at low invariant masses, which are due to γ misidentification events, responsible for the background at high invariant masses which is due to the γp→π0π0p and γp→π0ηp reactions.