American Airlines has deep pockets.
That's all that's needed for a lawsuit. Someone with lots of money.
Well I think that is in cases of shared negligence. But if you can’t prove causation, there’s no negligence in common law. Judges who rule otherwise are unjust unless there is an unjust statutory law in that particular state allowing for such nonsense, but I doubt the majority of people in very many states would go along with such a law.