In the case of the chameleon kid, it's very possible that the CTD program and the school see completely different kids. In the one environment in which being smart is cool, the child exhibits intelligence, and in the other environment, the child dumbs down deliberately. This is a common behavior among gifted girls in particular.

Ask me about the time my DD, who had been forming perfect letters since she was 3, decided she didn't know how to write a capital M anymore...