I wouldn't worry about falling because you forgot to unclip. I think everyone on this forum has done that a time or two. I've also been there and done that. What worries me more are the times when you're riding and minding your own business and some a-hole is the cause of you going down because you can't react and unclip in time. This seems to be happening to me quite often lately; yesterday being the latest episode. I would rather fall while stopped and get small bumps and bruises than when I'm moving and get larger ones.