That's exactly what happens. Just to make it clear again. You can not deactivate your own stick. If you push the red button and hold it , you have just deactivated the other stick. If the other stick is now moved without pushing on its red button, no inputs are commanded. The main reason for this is in case of a stick malfunction. If the other guy is flying and the airplane starts heading for the ground and he can't do anything about it, s/he'll ask you to push the red button. You then lock out the malfunctioning side, remove the faulty inputs to the flight computers. There are side stick priority lights in front of each pilot. A red arrow illuminates in front of the pilot whose stick is deactivated. The arrow points towards the other, active, stick. A green 'Capt' and 'F/O' light illuminate in front of the pilot who has control , but only if the opposite stick is not in the neutral position.