I wasn't there as one of those in the back and know nothing about the incident that sparked this thread but it was a very well reported incident at the time and one of those 'this has just happened' stories reiterated during training.
I saw someone nearly do the same thing from a French Puma at 200' above the deck when the French CM opened the doors and the Patrol Commander was keener than ever to get out - exercise in France, tired, bored of the noise...and keen to get on with the job.
The French CM grabbed our man just as he lunged for the door...