And he says it's a quantum jigglyboop designed to find neutrons in pickles.
That's a cute way of saying "What if he lies to me?"
He could have a steel pipe bomb with a little detonator on it and say "It's a barometer, the cylinder has a set pressure inside and this device reads the outside pressure" and I wouldn't be able to contradict him because I don't know.
I doubt the kid who made an explosive device is gonna go "Oh, it's a bomb, I was coming in to kill you all but you caught me. Here's how you turn it off. Let's go see the cops."

These weren't even high school kids. Unless you're dealing with Satan incarnate, I really doubt you're going to have a little kid toting something like that around. As per your description, the device
you described looked nothing like the one in the actual events. A pipe bomb is a pipe. A reactive material is found inside. The pipe about the reative material is not only casing but becomes shrapnel... Yeah. Nasty.
You'll note this also lookes like a bomb. You'll also note that although a bomb has wires (if it has a more sophisticated detonator), it also needs a charge. A plastic Gatorade bottle with wires in it does not have too many ways of hurting the general populace in the area... unless you beat them with it. Caution is good, but as I was saying, this got WAY out of hand.
A home made bomb can look like anything. Learning how to make a bomb is pretty simple as well. Heck, even taking an introductory chemistry class will teach you the basics of "blow-up-ology."
I don't know what his device looked like (though I'd like a look at it...), but I really get the feeling this was really, really overblown. As in ragingly stupid on the part of the VP. I'm saying this as I've had (a.) personal experience with stupid school admin decisions and (b.) heard/seen evidence of similarly stupid judgements (Remember the little girl with the empty shotgun shell? Yeah...). This may in part be due to bull-headedness in terms of discipline/control of the students, which is also potentially a massive problem. Common sense goes a long way. As we weren't there to hear what went on between the VP and the student, we can't truly judge the logic of the VP. However, I'm pretty certain the logic of the VP was very much lacking...
Can I point out how you say that a bomb can look like anything, and then, without seeing what it really looked like, decided the person overreacted? What if it really did look like a bomb?
How can you say any item can be a bomb and then lay into a person because they thought an item looked like a bomb?
To our friends at the Bureau, a very warm welcome.

Well, welcome to Advanced Terrorism/Spycraft 101. This is
not a class for grade school students. OHHHKAY, how do you get a bomb somewhere it shouldn't be? You put it in your shoes or some other crafty place that isn't conspicuous. Or make it out of a material that isn't conspicuous while being hidden in a crafty place. This is how spies and the baddies have been doing it since... long before you were ever born. This is very technical, involves a great knowledge of chemistry, and all manner of other things like so. It also involves tact. You don't show everybody that graphing calculator... that doesn't actually have batteries in the back. But then you weren't dealing with the devil child here, he has no motivation to do such a thing. To make a potent weapon out of such a small space also requires a hefty explosive which your common happy school child doesn't carry. And if that's the case, you might as well do a chemical analysis of EVERYTHING everyone has in the entire building. That's what I mean when a home made weapon can be made to look like anything. The desire to do that, however, is above and beyond most everyone - your elementary school student will concievably not do this.
I'm going to stop this before our good friends at the FBI think I'm some sort of dissident who must be warranted and searched. This ludicrous sentiment that everyone is suspect is over the long term quite harmful to the health of communities and nations. We're picking at the VP as no common sense was there: the student showed no signs of being dangerous, he did not act as a dangerous person would act (you know, sneaky/tactful), and upon questioning the student (if the VP did it at all - when he/she should have), the VP still showed no real competance. Councelling? The only reason the kid and the family might need councelling is for any distress caused by this "charlie-foxtrot." Anything else is unjust...