I forgot to clip out! The only thing on my mind at the time was the feeling of relief... so, needless to say, I took a spill.
I bet you almost peed in your pants, right?
Anyway, I fell on the 2nd ride (into a lane of the freeway), and again a bit later. But I haven't fallen since (about a year now). The key for me was practicing clipping out literally hundreds of times, at all pedal positions, both feet.