Light curves of an NIR and X-ray flare for two different choices of the particle acceleration duration. Top panel: NIR and X-ray light curves for the same flare as in Figs. 1 and 2, but also accounting for the decay phase. We show the results for two choices of the particle escape timescale during the decay: $t_{\mathrm{esc}}^{(II)}=R/c$ (solid lines) and $t_{\mathrm{esc}}^{(II)}\to \infty$ (dashed lines). Bottom panel: Same as in the top panel, but for an acceleration episode lasting 10 t_acc.