Ignoring collectivist thinking is a fault when people do in fact act in groups. It is even more so a fault when referring to the violation of rights, when rights only exist as a collectivist decision.

If you were about to meet this tribe, there is nothing you can do about the fact that you are a member of a Western culture meeting a member of a tribal culture, and your different groups--national, cultural, philosophical (in the sense of your strict individualism)--are interacting in important ways. Denying the problem by pretending there are no groups does not make it go away.