There are some sticking points. DNA drift between Native Americans and North-Asian Siberians, and their bones lines up well with the rough "23,000 years" number thrown about for N. American settlement.
One possibility is that it was a previous migration, maybe even Neandertals, one that had died out before the more recent Bering Strait land-bridge migration happened, or one that was much smaller in population and got killed/interbred with the 25,000 year old ice-age migration. (shrug)
100,000 years also puts whoever these humans or hominids were in the path of a few big climate change events, volcanoes, earthquakes/tsunamis etc. so dying out before what would become the Native Americans arrived seems like a distinct possibility.
Or maybe someone's new dating method is bunk, or got contaminated.