Their language, in their view, emerges from their lives as Pirahãs and from their relationships to other Pirahãs. If I could utter appropriate responses to their questions, this was no more evidence that I spoke their language than a recorded message is to me evidence that my telephone is a native speaker of English. I was like one of the bright macaws or parrots so abundant along the Maici. My “speaking” was just some cute trick to some of them. It was not really speaking.
Woah. See Blindsight and the Chinese Room principle. Is this not a real life situation mirroring what happened in Blindsight... but amongst the same species!?