The NCEA system for most NZ high schools is notorious amongst both students and staff for its rigidity and seemingly deliberate refusal to allow for critical thinking. While the restrictions in normal classes are alleviated somewhat, the teacher is still forced to adhere to what is most likely the most rigid educational system in the Southern hemisphere. When it comes to exams and tests in general, how a student writes, learns and expresses their knowledge are thoroughly restricted, allowing only one or two paths to academic success; a student has to memorise what NCEA markers want and essentially suck up to them. As a whole, it is thoroughly despised by most teachers, who feel extremely limited in their teaching approaches and believe that its only use is for when examinations come round, not for the other 80% of the school year.
So, from my experience, those who work in education encourage critical thinking, but are tightly limited in how students actually express it under the current system. That's only my experience though, some places in the country use the more lax Cambridge system, though that system is occasionally sneered upon by some universities here and prefer students raised under the NCEA system.