Sometimes you don't clip out until the bike is above your head, you're lying on your back, and someone is asking "man, are you ok" ... I mean it's just part of the game. That has only happened to me once, and oddly enough it took about 2.5 years before it happened. I did have a broken ankle earlier in the year, which has left my preferential foot to unclip with as also my preferential foot to rest my weight on when coasting to a stop. That has really wreaked havoc on my stopping game. What was always natural is now a chore, every time I come to a stop.