I suspect that the passengers didn't realize that they were doing something dangerous when they all ran away from the crocodile at the same time.
Panic is generally dangerous; people could have gotten killed by the scramble to escape the crocodile in any enclosed space, the fact that it was an airplane just made it worse.
An unusual incident. Are you obligated to be on the side of the plane with the crocodile if the other passengers are overbalancing the plane? To push other passengers over to the side with the crocodile?