Per Joerg:
No, but as Frank said he slipped off the pedal. I believe he slipped off
the left pedal first and that percipitated the fall. He was trying to
pedal harder and may have partially gone out of the saddle. Possibly he
wasn't used to that mode of powering a bike and messed up.

At first glance, I thought his left pedal spindle had broken - but your
explanation makes more sense.
--
Pete Cresswell