Avman
playing Devil's Advocate, there is, to my knowledge, no LEGAL requirement for a passenger to a) watch the safety briefing or b) refrain from talking. If it were so, it should be clearly displayed in the contract of carriage. Consequently, the RYR crew had no LEGAL recourse to throw the pax of the flight. I expect RYR will lose the case.
There is however a legal requirement for the Captain to ensure that
everyone has recieved an adequate safety briefing. If someone refuses to pay attention then he would perfectly within his rights to remove said person.
PS How well briefed would his friend and 8 year old son have been?