I've had a few clipless moments. They always occur at the end of a long ride when I'm wiped out. I'll clip out on my usual side, put my foot down, and the bike will decide to go the other way. Although one time I was following my wife on the MUP and she thought she heard something fall and hit the trail (nothing did) so she just stopped right in front of me. I was able to stop to avoid hitting her, but not unclip so down I went.