Zero-tolerance policies are generally stupid, because they are rarely written with enough care to ensure justice is done and injustice is not. If you’re going to institute a sloppy policy, you had better not make enforce it punctiliously.
When you do, you get asinine situations like the 17-year-old North Carolina girl who has been expelled from school because she accidentally brought a paring knife to school in her lunch box.
But that’s not the bad part. The really bad part is the school’s officials are lying to justify their decision.