I'm a bit confused by this. Antigua is a party to the Berne Convention, which requires them to recognize the copyright of works by authors of other Berne countries the same way it recognizes those of its own authors.

Can the WTO override this? I'd expect that all the WTO could say is that it is not a violation of treaties and agreements that the WTO oversees for Antigua to pursue this remedy for the WTO violation, but that wouldn't relieve Antigua of obligations under non-WTO treaties.

It's been a long time since I've read the relevant treaties and agreements, so maybe I've forgotten or overlooked something.