As I understood it they must put their name on the planes they inspect and work on. They must sign off that the plane is safe. If they are to be accountable then when they say a plane is not safe. I will go with them. Again they must sign off on the safety of the plane.
https://flydango.net/dissension-flares-into-lawsuit-filed-against-southwest-mechanics-union/
Here is the Lawsuit SWA filed against the Mechanics and details the actions the Mechanics took to ground planes just to hurt the airline during negotiations.