They are incorrect, but you are as well - airbus controls are not mechanically linked, save possibly on the A300 (which has a yoke not side-stick), but there’s

They are incorrect, but you are as well - airbus controls are not mechanically linked, save possibly on the A300 (which has a yoke not side-stick), but there’s less than 200 of these still flying - airbus sticks have a priority / takeover button, but by default dual inputs are averaged (this is also what happens in Boeings when you trigger a breakout apparently) - Airbus has a “dual input” aural alarm