You appear not to be well informed recceguy. A crew member deciding not to fly for any reason is not at all the "droit de retrait". A crew member can only claim not to be fit to fly or fatigued. The "droit de retrait" is something else. It is based on the Code du Travail, Articles L321-8 and following, and protects workers placed in a working situation that could cause imminent and serious danger for their life or health.
The Conseil d'Etat deliberated (after a request for clarification from the Ministère des Transports), based on the Code de l'Aviation Civile, that only the Captain has the right to decide on behalf of the crew if an aircraft can safely fly without causing any danger for the safety and health of crew and passengers (référence n°377.142 du Registre des Déliberations, séance du 12 Mars 1985). All the manuals in French airlines must be based on this deliberation, it is the law. Every crew member knows it, and no one except the Captain would never dream of claiming that right.