That's basically because the officer is an adult, and is supposed to be a trained professional. While the girl is just an angry kid. So, yes, most of the responsibility for this idiotic response belongs to the adult.
THAT is exactly what I mean. Just because we expect more from adults doesn't mean there should be no expectations from children and teens.
An angry teen who is encouraged to disregard authority is on the road to becoming an angry and volatile adult.
This thread is an example of this girl being rewarded for her behavior via the encouragement of everyone who is holding her blameless.