The letter indicates the traveler had experienced cruising before, even claiming to be a "long time, loyal client." with Cunard. My question is: Where you not aware of travel insurance? This is one of the most talked about issues that newbies ask on any MB related to cruising. And many on-line agencies promote travel insurance. Even the cruise ship companies in their literature have "written" information about the benefits of buying travel insurance.
Post this wherever you may... But in all things in this world, it is your responsibility to know the terms of the contract; and yes, it is a contract when your purchase!
I'm sorry the letter writer has cancer and sorry for the inconvenience and suffering it has caused.