For some years there have been tantalizing hints of evidence mainly in Mexico and south America that settlers from Siberia had crossed over the Bering Straits into North America before the undisputed stone tool users arrived fifteen thousand years ago. The Clovis culture is well attested to with habitation and tool evidence at 13,000 years BP
Humans have been using stone tools for their quarter million year history and earlier human-like species have done so as well with a record of lithics (stone tools) reaching back two and a half million years.
At the new site in California archeologists really need more evidence especially in the area of lithics before the news item will be accepted as a scientific fact.