No, I think it's more likely that the single man scenario could have happened a thousand times - once every century - and left less evidence than the first breeding pair did in the two centuries after their arrival.
More practically, since it is certain that humans had made it from Africa to at least Indonesia by the time under discussion (a journey necessitating the use of some sort of watercraft for several steps of the journey), then it is not a huge leap to put a population of humans on the Korean/ Kamchatkan coast, living a hunting/ gathering/ fishing lifestyle, and to have them lose boats to a storm from the west on a regular basis (not enough to threaten the populations survival, just part of the regular attrition of death in fishing communities ; my Best Man's home town lost three generations of one family in one boat only about 30 years ago). The few boatmen who survived the ride along the pre-Aleutian chain, past the coastal glaciers of pre-Canada and pre-Cascadia ... eventually might arrive at pre-California and choose to stop. "Here, we can repair, re-equip, collect stores, and figure out how the fuck to get back home." And leave no population behind, because they don't put their valuable women onto the dangerous boats until they're damned sure they know where they're going.
Up-thread some people mention the Vikings going across the North Atlantic, island hopping. They don't mention the well-attested history of pre-Viking voyages (e.g. the "St Brendan" legend) that probably indicate the distorted tails of the few storm-tossed fishermen who did finally make thir way back home ... to start a legend, and to give their descendants the idea that there might be something worth going over the horizon for. Generations later, Erik Thorvaldsson and Ingolfr Arnarson knew damned well there was land "out there" when they set off to settle Greenland and Iceland respectively.
I've never believed that the only population who settled in the Americas were the ones who followed the mid-Canadian ice-free corridor. Not when the coastal route was also available. Unfortunately, archaeological evidence for the coastal route is typically at an elevation of -50 to -100m, making it challenging to identify and dig sites. In that context, this is a very interesting report. Even if I do have doubts about the final numbers for the dating.