I don't think that everyone will fall down while getting used to clipless, but it sure seems like a popular trend. When I got ym SPD setup a few months ago, I was doing really well for about a week when I fell over at the end of a ride. I was in my driveway and coming to a stop. I unclipped my left foot, but when the bike stopped, it began leaning to the right. I wasn't quck enough and ate pavement. No notable damage to anything, and my foot even unclipped when it hit the ground.