After 50 miles on clipless (25 more yesterday), I still haven not fallen. I almost fell yesterday, when I stopped behind a cyclist, and tried to pull my foot out of a (nonexistent) toe clip. when I pulled my foot up and backwards to get it out of the (nonexistent) toe clip, it just moved the pedal+crank, it would not let my foot go. I almost fell at this point, but there was a railing for me to hold on to. Had that railing not been there, I would have toppled over.