The original forensic archeologist made an error which was corrected almost immediately.
Kennewick Man was not caucasion and was not ever caucasion. The original forensic anthropologist’s expertise was on modern characteristics. That’s why he made the initial error. Once they recognized the antiquity of the burial, appropriate experts were brought in. The report said that he could not be placed in any modern group but clustered most closely with Pacific Islanders.
None of that means anything to modern people. No one has the same charcteristics as their ancient ancestors. For instance, did you know that Caucasions, Native Americans and East Asians were closely related that long ago?
30,000 YA is longer than the guesses of when the ancestors of Native Americans arrived on the continents but it’s not longer ago than the genetic guesses when they separated from their old world ancestors. Maybe the Berengia theory is wrong. Maybe they simply evolved on this side of the land bridge.
The other thing I was going to point out is that some South American Indian groups are thought to be of Polynesian origin.