Atheist Amazonian tribe.

[John V]

Depends on how you define 'god'. Zeus, for example, was not omnipotent, but he was still considered a god.

Yes, it depends how you define god, and I think that a spirit being which lives above the clouds and sometimes gives commands to humans would fall within most atheists' definition of god. If there were an atheist-only area here and someone there said that there's a spirit being which lives above the clouds and sometimes tells her what to do, she's probably lose her access to the area, don'tcha think?

However, line one of the quote says: "According to Everett, the Pirahã have no concept of a supreme spirit or god". Fairly unambiguous and explicit, no?

Yes, unambiguous and contradictory. Seems his own deconversion is biasing his take on episodes he described which speak for themselves.