I never fell while learning to use clipless. The one time I did fall, was about 6 months later. I was stopping at a light, on a slight uphill. I still hate those kinds of intersections, because I feel like I can't get started. Anyway, I am not sure what I did, but all I know is that I was lying in the middle of Rt. 62 and 117 in Stow, still clipped in. My bars were all twisted and my knee was trashed. My husband was able to get the bars fixed with his tools, but it was embarrassing.
I hate riding without being clipped in. I have campus pedals on my hybrid and mountain bike. I suck at mountain biking, so unless it's really non-technical, I tend to ride with one foot not clipped in... someday I will learn.
About a month ago I was riding my hybrid to the train station. I decided to wear regular shoes, so I wouldn't have to deal with changing shoes, etc, before getting on the train to the city (my ride is like 4 miles). I was stopped in a long line of cars making a left in Concord Center. When it was my turn to go, I could not get going! With one foot on the ground and the other on top of the pedal, it just seemed, well, not right! My foot flew off the pedal. Very awkward and embarrassing. And the ride home, besides being my first night time ride was torture, because it's all up hill.