Thami's actions to betray Mr M and join the comrades are justified?

This question calls for your opinion. There is no right or wrong answer.

Over the course of the play, Thami's loyalties to different people are tested. At the beginning, Thami's strongest loyalty is perhaps to Mr. M. He does as Mr. M wishes, competing in debate and leading Mr. M to believe that he might go on to higher education. However, he also knows that he must be loyal to himself and his people, and he starts to feel conflicted about the education system set up by the government for black South Africans. Once Isabel enters his life, he is also loyal to her for some time. They practice together for their competition, meeting regularly and supporting one another by researching and studying. However, after some time, he breaks her loyalty as a teammate and friend by quitting the team and saying that he probably cannot see her anymore. His loyalties have been pulled away from both Isabel and Mr. M by his new loyalty to the Comrades and the Cause, which come to dominate his life choices.