This is what happens when we have “zero tolerance” rules in which nobody is allowed to use common sense judgement.
A zero tolerance rule about weapons may have been adopted with the best of intentions, but, any rule should be administered by someone with reasoning and thinking abilities.
This reminds me of the case of the 6 year old boy who kissed a girl, and they sent him for sexual harrassment training/education.
Some situations just yell for a law suit against the school.
I refuse to credit the originators of such policies with good intentions. They may think so of themselves, but what they are really doing is building a machine which works without individual initiative and responsibility. These are, after all, exactly the things that the schools exist to suppress in the students, so it is only natural that they should follow such a pattern in their own administration.