Originally Posted by Jet Jockey A4
..."If in doubt from what I understand there is a “Master” switch on the left side stick that disables the RH side stick"
The switch is called "takeover priority" and there is one on both LH and RH sticks. If the switch is pressed this is enunciated with a red warning light plus a "priority left/right" voice warning.
The other stick is not permanently disabled. After either left or right side takes over, the other side can take it right back by pressing his own switch. This happened with AF447, repeatedly.