The "X button" could be a button to help him react properly. I know he is a world class driver, but when something unforeseen happens, all people react instinct

The "X button" could be a button to help him react properly. I know he is a world class driver, but when something unforeseen happens, all people react instinctively, rather than consciously. A way to combat this is to train a movement, like slamming the foot in the footrest, or pressing a button. It buys you that fraction of a second to assess the situation and act consciously, rather than just react.