Truth be told, I'm guessing everyone who had tried clipless pedals has fallen over at least twice...
Once early on when just learning the technique, and a second time, long after mastering the technique but "distracted" for a moment. That's all it takes. A very odd feeling isn't it?
(...let's see...if today is Wednesday the 15th then next Thursday is the...unclip right foot like so..wait left .. LEFT.....LEFFFFTTT...... "####" .....)
Yup. Been there.