There's no relative scarcity of ignorant and authoritarian schoolteachers, but consequences are likely to be confined to school, not involve law enforcement, and parents and pupils are more likely to knuckle down rather than fight or go to the press.

So, taking "such behaviour" much more broadly than this specific incident (and of course granting that Europe is a big and diverse place) - if a kid is found hacking school networks, or distributing a satirical magazine, or bringing possibly inappropriate or dangerous items to school, the schools are just as likely to crack down (even if it infringes the pupil's legal rights) but the matter is likely to end there without ruining the pupil's education. Or making the school administration change its behaviour.

Personally I think the situation as I have described it is favourable. Ideally schools wouldn't be administered by petty tyrants, but as long as everyone finishes their education with a blank slate it's fine. Keeping the police away from schools as much as possible would be a good start.