Epic fail

How do both crank arms fall off at the same time when one is bonded to the axle? I can see the non-ds coming loose and falling off but not both. Also why would the crank be that high in the air? The don't have a massive tendency to bounce.

The axle could well still be attached to the RH crank but can't be seen in the pic.

This happened to me when I forgot to check the bolt that holds the LH crank before a ride, it fell out because stupid FSA thread it so your pedalling action undoes it, the arm came off, I went down, the RH crank, chainrings and axle went bouncing off up the road just like in the pic. I was clipped in at the start. I still have the scars on my hip if you don't believe me.