Lui challenges our conclusion that magnetic reconnection triggered the onset of a magnetospheric substorm. However, Lui incorrectly uses the auroral electrojet index instead of ground auroral and magnetic field pulsation signatures to determine substorm onset; single velocity and magnetic field components instead of full vectors and particle distributions to identify reconnection onset; and preliminary auroral electrojet–low index (AL) instead of ground magnometer, auroral, and magnetotail data to claim pre-existing activity.