Been using clipless for about 5 years now but never had trouble unclipping until a few weeks ago. I was sitting at an intersection downtown and having a good old time after beating all of the traffic and listening to some fast tunes. I guess I was rocking a little bit, my right foot was on the ground and my left was clipped in. I rocked too far to the left and could not unclip in time, splat, nice scrape on my left knee. I managed to get up and compose myself before the light changed. I noticed that after I fell, the van behind me had backed up. I assume it was so they'd be out of the way if that dork on the bike ****zed out again.