A plane makes an emergency crash landing on a deserted tropical island. Two dozen survivors must fend for themselves until help arrives. All of them are from large cities, and none of them has camping experience. The survivors find it impossible to gather enough food, and everyone begins losing weight. One person spends a lot of time by himself and figures out how to catch fish. He brings fish back to camp. Others ask him to teach them how to catch fish. He refuses, but offers to share the fish he has caught with the other passengers as long as they take care of the other camp chores, such as hauling fresh water, gathering firewood, and cooking.

From story above, which ethical theories (kantianism, act utilitarianism, role utlitarianism, social contract theory) suggest the shermans position is morally wrong and suggest the shermans position is morally right?