Well since "we" as the general public do not really know why the Indonesian's decided to not allow the flights to continue we cannot know that there was any incompetence.
To prove incompetence a party would need to know exactly the terms of the objection by Indonesia and furthermore prove that VA/Tiger could/should have reasonably forseen that outcome. Then you have proved negligence. Good luck getting access to internal company documents.
As said above, that is why one purchases travel insurance.