This rule is applied when you have called Shotgun and are waiting for the doors to be unlocked. If you lift the handle while the doors are being unlocked and therefore cause the Shotgun door to remain locked, then you are Voided for that ride. Once someone has balked, Shotgun becomes available for the other passengers to call.
2.7.1 The Hand on Door rule does not apply to a Balker. Balker does not get Shotgun by simply continuing to holding the handle or touching the door once they have cause the Balk. Other riders may call Shotgun until the Balker Sits Down.
2.7.2 If no one calls Shotgun again before the Balker Sits Down the Balker retains Shotgun.