That sucks. Glad that you are okay other than a bruised ego. I wiped out quite a number of times when I first went clipless and one of the things I quickly discovered is to lube the pedals before each ride. I got so frustrated and felt like such a loser that I couldn't master these pedals that I put a shoe on the pedal without my foot being in it, and I could barely pull it off using my arm! The pedal had seized up. Now I love clipless. I just make sure to use a little White Lightening before each ride.