obviously you've never worked with people. people in general. today's population that will bring a law suit on you for anything they possibly can. the contract doesn't read:
i am not going to pay attention so if i'm napping when the officiate gets to the first kiss i can't be held accountable.
Actually, it sort of does- however you've obviously not worked with litigious people. A contract doesn't stop a lawsuit, it may help you win one, but that depends a lot on the overall wording of the contract, how it's presented to the signatory, what discussion ensues and what actually happens at the shoot.