I'm pretty sure you search the web, you'll see a legal case that makes it the captain of the vessels problem UNLESS the mooring owner knows (or has reason to believe) that there is some problem with it. Example from the Fifth Federal Circuit: http://navwaters.com/2011/08/31/mooring-the-respective-duties-and-responsibilities-of-vessel-and-wharfinger/

Having said that, the Landlord that the rented the house could have "mucked up" that issue by something the effectively warranted something.

An insurance company might settle a case rather than go to court -- depending on the magnitude of the settlement and the "forum" (location, jury trial risk, etc.)

Certainly if you're going to leave your boat on a private mooring you might ask the questions about what is it connected to, how long since it was inspected, etc., etc. If in doubt, it certainly would be worth a $150, or so, to have someone dive it and check it out if you're leaving something that you care about "hanging" out there. ;^)))