India could have simply chose not to resolve the issue in the international court, forget about accepting the verdict. International court cannot take up any case without the consent of all the countries involved.
Perhaps, India could have done the way you profess. Also similarly China could hove held on NE after 1962. China left NE and similarly India left our part of BoB. It is how international relationship is maintained. But, never I have read one Chinese talking childish like they could have held the entire NE bla bla bla. It is only Indians who speak of generosity by vacating our sea. Anyway, buy our goods, we will all say India is generous.