You said the GATE is four-tiered. So what is the chance of upward mobility or will they use this testing to define which level he would be at forever with them? What is the difference between the levels? Is it appreciably enough different that you need to advocate now vs. later?

Will he take MAPs at a later date? Like at the end of the year? It could just be that he was bored with the math or they did the testing on an off day. But it is very much a "gifted thing" for them to not be careful and overconfident with math problems that they feel are beneath their intellect.

Do you have other testing results to fall back on?