Well, the guy never came back to get an answer, so... I am guessing he figured something out or gave up.
I know what Pete would have said - ANOTHER (truly) good reason to use an independent travel agent whose job it is to make sure you get all of the details right - and who also KEEPS separate documentation of every transaction you make - because it is their job to do that.
The first guy admitted he only bought insurance for the part of the cruise he completed, and not for the part he missed. I think in the end, no matter what, even Judge Judy would say "you expect to get something for nothing? - that isn't how life works, mister!"