Wiggy - refusing to read the safety card or look/listen to the briefing is not a breach of contract or a criminal offence. Refusing to follow the instructions contained in the briefing or on the card when being required to do so by a member of the crew, is a breach.
If the former were true, there would be lines of people being led of aircraft around the world everyday.
Our numpty couple were dealt with because they broke the law regarding use of mobile phones while being instructed not to.