After over 400,000 miles in clipless, I haven't had a single bad episode. I did witness a couple of mishaps. Back in the early '80s Cinelli came out with the first clipless pedal system. The cleat slid onto two rails and you locked in by pulling out a tab on the side of the pedal which caused a post to rise into the cleat. Obviously, one had to remember to push the tab back in to get out. This wasn't much different than remembering to loosen the toe strap to get out of toe-strap/cleat set-ups. The wreck that my friend had with these pedals prompted the nick-name "Death Pedals" for them. It turns out that the spindle was a bit undersized and was thus prone to failure. In his case, it failed in the middle of an all-out sprint down the main street of a neighboring town. He had some ugly road-rash and a fifteen mile one-pedal trip home (all flat terrain).

The only other clipless incident I ever saw happened many decades ago to my wife. We were riding to the beach and were both track-standing at a red light. She was behind me and there were a couple of teeny-boppers in a convertible next to me. Unbeknownst to me, the teeny-boppers were checking me out. My wife was laughing so hard she fell down the side of an R.V. that was behind the teeny-boppers. I happened to turn around just in time to see her go down. Fortunately, the driver of the R.V. saw the whole thing and waited until he was sure she was clear before he proceeded.