We had a similar situation in 1st grade. The more I tried to communicate with the teacher, the more defensive she got. At first I was confused and dumbfounded at how and why I kept offending her. When I finally met with the principal she suggested a change of classroom (my son wasn't the first to have issues with the teacher) and there was an immediate and positive change. His second teacher did not challenge them as much academically and my DS is HG+, so we were worried he would be bored with the second teacher, but her more easygoing manner meant he could choose his own reading material (5th grade level in 1st grade) and that really made a huge difference for him.
We were all (DH and I, the principal and the new teacher)worried about anxiety at the time of the move, but it was really just a breath of fresh air for him.
In my long-winded way, I'm suggesting that you go with your gut and move him soon as is practical. Your situation reads like a clear case of "it's the teacher."
