As far as unintentional goes, I agree, for the reason you've given.
This incident, though, I think is a little bit different. We've got someone who, at best, has been "criminally negligent" - meaning that while she might not have meant to cause a disturbance, the circumstances were such that she should have been aware of that very real possibility. In other words, would a reasonable person walk into a situation with what could reasonably be interpreted as a threat, and expect that other reasonable people would not be disturbed by it? Sorry for the excessive use of "reasonable," but that's the measuring standard for most legal situations.
I just don't think there's any way that you could reasonably walk into an airport with something looking like an explosive and be blissfully ignorant of the disturbance that is bound to cause.
As I've said, I don't like the idea of a police state where the State (aka, the police and the Man) gets to serve its own interests to the detriment of all else. Regardless, this situation has to be punished - we, as a society, can't have rabblerousers constantly baiting the police. It costs all of us time, money, and exasperation. As a worst case scenario, what happens if somebody does something like this again, and while police are responding to it, a 7-11 gets robbed which might not have otherwise been robbed had the cops not been tied up with a bunch of BS?
Dad enforced the stupid penalty 
)
I have no doubt she was trying to provoke some 'response' or media attention. And she got it. 
