That was 99% confidence that the response will be disproportionate to the magnitude of the attack, if an attack takes place, not 99% confidence that there will be an attack. My odds of an attack were 50%. I think an attack is fairly unlikely to be on an aircraft - security is relatively tight on aircraft compared to other possible targets.
You must specify disproportionately high, or disproportionately low.
I would like to propose this as a thread for people to write in their predictions for the next year and the next decade, when practical with probabilities attached. I'll probably make some in the comments.