Give the man a prize. I wish there were a Nobel Prize for Common Sense. Very glad to see that Norway is not following the general (and useless) trend of "more surveillance and fewer civil liberties" after things go boom.
It takes serious resolve and uncommon grace to rise above the gut reaction, keep calm, and remain focused on what really matters.
I think it's a learned reaction. Car accidents pose a greater threat than any terrorists, we're not terrified of cars are we? The threat has been played up by our fear mongering media, an extension of our military.
By contrast, if a person found an unnoticeable way to sabotage all cars in a city, making them slightly more likely to crash, and didn't seek credit, this would not be terrorism even if the act killed very many people.
You might say that our tolerance for the danger of driving is logically inconsistent with our expectations of perfect air travel safety. Is that irrationality a learned or innate one? Probably a mix, but certainly at least partially innate, similar to the human tendencies to value immediate rewards much higher than future rewards, or the loss aversion bias.
I see where you're coming from, but I feel it's too subjective. The massively disproportionate action is not under the control of the terrorizer, but rather the publicist. The media really controls who we consider to be "terrorists", rather than any empirical metric.
If we have counter-terrorist groups who just go after terrorists, shouldn't we define who terrorists are? We start using words like "cyber-terrorists", and now we're all included. I just find no value in the semantic classification of boogie men except for expansion of our police state.
Good sense and sound judgment in practical matters