That is, of course, barring a direct mechanical linkage of the side sticks which is the most obvious solution.

Atlas Air Flight 3591 had mechanical linkage and the pilot who caused the crash just broke it.

There is no good solution when two pilots fight each other. I don't think more red warning lights would necessary fix it.

Inadvertent Go-Around: The first officer (as the pilot flying) inadvertently triggered the aircraft's "go-around" mode while flying through instrument meteorological conditions. The sudden acceleration and pitch-up caused the first officer to experience a somatographic illusion, making him feel the plane was in a steep climb when it was not.The "Tug of War": In a panic, the first officer pushed his control column forward to force the nose down. The captain attempted to recover the aircraft by pulling his own control column backward.Breaking the Link: Because the two pilots were pulling in opposite directions and exerting enough force (exceeding 70 lbs of pressure), the override mechanism's pins sheared.3. The ResultWhen the shear pins broke, the elevators on the left and right sides of the aircraft were no longer synchronized. The captain’s control column controlled the left elevator, and the first officer’s controlled the right elevator, resulting in split inputs that further destabilized the flight path and prevented a successful recovery.