Again, I'm going to say, if you see a kid showing off an unknown electronic device to lots of friends at a technical school, and your first thought is it is a bomb, my first action should be to call in the police, then you're in a very scared place, and one that is not mathematically justifiable.
You could argue that it's the correct decision. But for the police to then go even further is just absurd.
There are two different parts to this, and I'm only arguing one.
If someone sees an object they think might be a bomb, then yea, they should go tell someone who will probably call the cops. And for living in a scary place? Kids use bombs, that's what all the quotes are for.
Do they use bombs all the time? No. Is every school going to be hit with a bomb? No. I could even fathom that there have been more bombings than kids bringing in their homemade motion detectors but that's all speculation.
School safety does not work like "If you see something you think might be a bomb, don't worry, it's probably not."
Again, there is a difference between "I don't know what that is" and "that looks like a bomb"