After making a three-point shot, the visiting team player turns to the crowd and uses his hand to make a shooting (finger-gun) gesture.  This should have been recognized and penalized with a technical foul as an unsporting act.  However, none of the three officials saw the gesture.  The Train Official needs to watch the shooter all the way through the motion.  Had he done that, he could have seen the gesture, but he was already turned and heading down the floor.