Originally Posted by
scirocco
Technique tends to go out of the window at maximum effort, particularly when you're standing up and throwing the bike around at god-awful angles. You foot came out of line with the pedal at some point in the stroke and it unclipped as it is designed to do.
I had considered this as a possibility. But I probably make a maximum effort like this once or twice a ride and this was the first unclip. I actually hope you are right, then I can continue to be lazy and use my 1980's technology.