If the principal, main teacher, and counselor are able to convey specific strategies for teaching your DS to the PE teacher in a form she'll accept, that may be the best way-- you know the culture of your school. Teachers in general hate being told how to teach, so hearing it from a peer can be better for them than hearing it from a parent.

On the other hand, if you think you'll be working with her for years, the more you can build a relationship with this PE teacher, the better.

Hard stuff.

DeeDee