Maritime law is complicated because once out in international waters laws don't really apply because, well who's law do you apply? But the courts have already addressed whether or not cruise ships can be held liable for what their guests do when drunk. It boils down to if it is not something that they could have anticipated happening. I pointed this out in a previous thread here:
IN - Grandfather charged in cruise ship death of toddler Chloe Wiegand
Hypothetical situation: Mr Smith is living it up on his cruise and has had several long islands over the past 3 hours and can no longer feel his face. Deciding to go for a walk he stumbles around and ends up on the top deck and is just enamored with the way the moonlight sparkles on the water. He leans over the railing to get a better look and goes overboard. Even though the ship got him drunk the ship isn't liable because they couldn't have anticipated that he would intentionally lean over the rail in a way that he'd fall off.
Same night but different scenario. Mr Smith goes down to an unfamiliar floor that is not restricted and finds a door to the elevator mechanical room unsecured, left by some careless employee that had been trying to fix it earlier and hadn't realized when he left for the night that he hadn't resecured it. Mr Smith goes in because curiosity and ends up dying in a horrible way because he was too drunk to not realize he was in a dangerous area. In that instance, the cruise line would totally be liable, still probably not for letting him drink so much, but for the fact that they knew that was a dangerous area that guests shouldn't be in and steps were not taken to make sure it was properly secured.
The window falls into the first situation and would be covered by the precedent of the other cases. The windows are located at levels that are chest high on an adult. There are railings in place to keep people from leaning too close to the open windows. The ship has passed inspections by the Coast Guard and other agencies and those windows are in compliance with regulations. No one could have anticipated that SA would have put a helpless toddler on that railing in violation of ships saftey rules in front of that open window. SA created the hazard, not the ship.
Precedence is the term. And yes it does exist. See above. So that combined with the fact that Chloe is the first child since at least 1995 as available by public documentation to have ever fallen off a cruise ship, the family really doesn't have much of a case that RC is at fault.