This seems strange, and I suspect the truth lays somewhere in the middle. I never accept anecdotal evidence I see on the internet because it is just one side of the story and will of course be biased. How normal is it for a cruise line to discern cabin damage and suddenly restrain passengers on debarkation day? I mean, you are typically gone before a cabin steward even gets in the room. And even if they did, what legal authority do they have to detain you? Certainly not for a damage claim. This sounds fishy to me and I view it with a jaundiced eye.