I've only fallen once since I got my pedals. It happened because I panicked. A car cut across my path and I had to stop suddenly. I unclipped on the left and leaned to the right (the side I usually unclip on). By the time I realized what I'd done it was too late. The thing about this is that I would have done the same thing with toe clips. I've fallen with toe clips so I know how fast I can get my foot out when the other foot is already out and there's no way I would have been faster with toe clips.

So I have to say I've never fallen because of my pedals. They actually have probably saved me a few times b/c they're easier to get into and out of.