Thank you so much for your input. The district coordinator is the decision maker. She is the one who said she doubted he would qualify on a retest. She said she knows it's a tough spot, but all kids are different, etc. I'm not sure she really understands that it's a tougher spot than it is with regular siblings.
I think another issue here is that she knows we pulled our daughter from the district school and put her in a charter school for gifted students. She probably guesses that if both our sons qualified, we'd put them in the charter school as well.
Our insecure twin doesn't seem to have significant anxiety in general, but gets anxious and atsy on days where there is no school and he doesn't get his math fix! But he is a sensitive little guy and certainly could pick up on the attitudes of the adults around him.
I will look up Dr. Amend. We could travel to the Cincinnati area for testing. I'm so grateful for your thoughts, both of you. So glad to have found these forums.