If cheating with some bluetooth headset actually worked, something is deeply broken with your academic system. All that it proves is that you give out participation awards to people who can memorize facts over actual problem solving. Memorization doesn't take a lot of intelligence.
If the implant played back an audio recording of his notes or something, then sure. But if it allowed the student to communicate with a medical expert during the exam, then even an open-book exam not requiring memorization could be exploited that way.
