I haven't fallen over due to being clipped in but came have come close to not getting unclipped. The 1 wreck I did have while being clipped in caused injuries that I don't think would have happened had I not been clipped in but I was being stupid and not even platforms can fix stupid.
Another thing I do with clipless that wouldn't I be able to do otherwise is reset my pedals after at a stop. When I ride up to an intersection of stop sign I put my left foot down while leaving my right foot clipped in. Then when I go to pull out I'll pull my right pedal back to the top of the stroke.