[pvaldes]

Not necessarily. Can be also a contamination from an external source of DNA. The article claims a mixed chilean-european DNA but we don't know how many moved humans had touched this skeleton before

And there is the fact that we share DNA with other species. It seems [1] that we shared a 93% of DNA with Macaca mulatta for example.

[1] https://www.livescience.com/1411-monkey-dna-points-common-hu...

[bordercases]

On that second point, charitably we can assume that they found a marker which is uniquely human. Although yeah, could be contamination.