This is more common than not. There is a limit of the amount of fuel a plane can take because of max takeopff weight, size of the tanks etc. If the detour is longer than expected they will not have enough fuel.
I remember when Cathay was flying 747s from LAX to HKG they had to land a few times per week in TPE to refuel.
I would expect that in this situation the pilot would select the best suitable airport. Not sure if any other suitable airport would have had 340 towbars.

Keep us informed if you succeed getting compensation. (other than a few M+M miles) I believe you will have a very uphill battle.