I've ridden SPD for a few years, and toe clips for a few years. I've never fallen as a result of either one. I just got on and rode, never had a problem. I do make sure to clip out about 5 seconds before I'm going to stop, so if I have trouble (I haven't so far) I can bail out by getting to a wall or post or something I can catch myself against.

I really don't have a strong preference either way, toe clips or clipless. I'm riding clipless right now because the cleats were already on my current set of shoes and I found the SPD pedals first when I was swapping out my winter platforms a few weeks ago.