In this paper we reported the analysis of the relaxation dynamics through a conical intersection in a twodimensional retinal model and fully based on the exact factorization. The aim of the work is to validate approximate trajectory-based results obtained by applying CT-MQC and CT-TSH against quantum wavepacket dynamics and against quantum trajectories, which represent for us the best trajectory-based results accessible within the exact factorization. To propagate quantum trajectories, we calculated numerically the time-dependent vector potential and time-dependent potential energy surface from the solution of the coupled electron-nuclear problem.