No, their info was correct. The repo cruise went all the way down To the ABC ISLANDS, which are defined in the Act as being distant Foreign ports.
To go from one US Port to a different Us port you must visit a distant foreign port
to go in and out of the same US port, any foreign port will do.
boarding in Key West would have turned the cruise from a closed loop cruise where any foreign port would work, to an open loop cruise, where the ABC ISLANDS or some other distant foreign port would have been required