I fell today during a group ride. I have been riding clipless on my hybrid for about a month while commuting without any problems, but I was exhausted after a series of hills and was too weak to pop my ankle out enough. So I fell. I did roll into the fall, so at least I managed to suppress the "tethered gazelle" impression I did the first time I fell, where you are trying to leap off the pedals and they won't let go. Hopefully my second fall was marginally more graceful.
It was less painful anyway. Now I'm riding with the left foot really loose and a tighter clip on the right.