Thoughts
They apparently filmed right at the actual location of his death.
They did read up on some of the science. For example, the archaeobotany indicates that he climbed very high, came down again and then went up again. This is on the basis of pollens they found on his body. Different pollens grow at different levels, depending on whether the trees are deciduous, coniferous or nonexistent.
Seems odd that all the people in this film live in such an isolated way. Wouldn't it be more likely that they would live in tribes so that they would have more protection from small bands of raiders?
They don't explain how he happened to own such a valuable copper axe, which in today's terms would be about as valuable as a Lexus.
The film is also terribly violent. I don't see why the raiders even started their attack and then did not take any of the people or materials they could have gained from it. They just destroyed for no reason.
It also seems they had an extensive cache that they just forgot about and never tried to reclaim. Odd.