I agree with the other's comments. Not only that, but I don't think you can rely on this teacher to help your child out in the long run:

We are also trying to get our son accelerated at this public school and this teacher's testimony I suppose would be important.

I'd also suggest investigating your options. Of course, all of this can be done in a nice way, but this one does seem to need to go up the chain of command.

Good luck.