I hate to say it but you are never totally free from the possibility of falling while clipped in. I almost feel yesterday. I was at an intersection and was about to take off. I only had my right foot clipped in when I saw a car coming from the left. Went to put my left foot back down but the cleat stuck for just a moment to the pedal. It wasn't clipped in but just caught on the pedal. I almost went down. It was kind of funny because as soon as it caught and I started going down I was thinking to myself, "Man, I can't believe I'm gonna fall." Luckily it came out at the last moment. So I bet even those that have been riding for years go down every once in awhile. But at least not as often.
As we must account for every idle word, so must we account for every idle silence." ~Benjamin Franklin