Look in the floor for the plastic plug that fell out of the hole covering the release button. It has a stud on it that holds that button in which you pressed to get the key out. Should not have anything to do with shift lock. When I got my most recent GTP, it was missing that piece and had a wadded up business card holding the button up. I left it, works fine. If someone has been into the steering column to replace the turn signal combo switch or something and the plug is there, its possible that something else is broken on the plastic cover and not holding the halves together tightly. That could let the plug drop down, even if it is present.
