One positive message I'm hearing from you, quantum, is that the teacher is self-aware and self-secure if she feels comfortable openly disclosing that your DS out-scored her on the test you referenced. Perhaps you can sit back and observe for a few weeks before acting. Then, if your DS' needs truly aren't being met, you'll likely have an advocate for bringing in AOPS or EPGY in the teacher.

What is to give light must endure burning.