I wonder if this resembles a standard game-theory game. I think the approximate payoff matrix is as follows, if we say -8 for congregating on either side and -2 for anyone on the crocodile side of the plane:
Croc Side | Away Side
CS -10,-10 | -2,0
AS 0,-2 | -8,-8
*starts digging through Wikipedia*
It's not quite a Volunteer's dilemma, because everyone-cooperating is still bad - it's actually an El Farol Bar problem. (Presumably you would be able to react to other's moves, but only after the initial rush - said rush probably already destabilizing the plane.)
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.
Also note (and I blame the evil effects of the trolley problem) that it didn't occur to me or anyone else to get or stay on the crocodile side of the plane and try to inspire the other passengers to do the right thing.
If I'm reading this correctly, the alligator didn't actually harm anyone EXCEPT by way of causing the plane crash.
So this would be kind of like a trolley problem except for the train has time to slow down before it hits the five people if you jump in front of it yourself.
Looking at RobinZ's payoff matrix below, I can't imagine how being on the crocodile side is actually worse than everyone running to the away side. It has to be a very small crocodile to fit into a carry on.
I want to know why someone didn't just catch the croc so people would stop panicking. I've picked up a baby alligator before; the crocodile couldn't have been that much bigger to get on the plane as described.
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?