The crew member who failed to secure the chock is at leat as responsible as the pilot.
That said, "hot-dogging" is GOING to happen, and the best way to deal with it is to ensure that both the aircrew and groundcrew have prepared for ALL potentialities.
Think about it: You've got young adults controlling spectacular machines! It's just human nature to experiment with the toys you have!
there is a hilarious video floating around the net of two guys doing a loop/dive in a plane. in the background you can see a dog floating in the air.
My son flies and jumps out of these Marine Choppers all the time and I worry more about him dying in a crash than I do when he's out in the field or on the water.
There is a time for daring flying and there is a time not to screw around. If a group of grunts took target practice and tried shooting things off peoples head they would be as stupid and guilty as a Chopper pilot screwing around hot dogging in training.
Do I drive more carefully when my family is in the car with me? Yes, I do. I don't hot-dog to delight the kids in the back.