I do think the author overstated the case; I think when he says a Nobel prizewinner is 'winging it', I interpret it to mean in their process of coming to understanding. By definition, people like Nobel prizewinners or billionaires had multiple turning points in their careers where they made decisions under uncertainty. And by definition, uncertainty means chance is involved. At those points they were winging it and could easily have been wrong. Just like our coin flipper.
Similarly, in a championship chess match there will be points where even the most skilled player in the world may be uncertain as to which move is best. At those points, they too are winging it. If they intuitively make the best move without being able to fully explain why they are making it, does that not prove the author's point?
Similarly, in a championship chess match there will be points where even the most skilled player in the world may be uncertain as to which move is best. At those points, they too are winging it. If they intuitively make the best move without being able to fully explain why they are making it, does that not prove the author's point?