Statistics and probability are tools humans use to predict outcomes of the world, they are not necessarily accurate reflections of the mechanisms of the world. Maybe I'm strawmanning the author here, I don't know. I may read the full book at some point but probably not yet.
There may very well be a limit where events are random (such as particle decay), but surely even fully determined events can have probabilistic outcomes, when aggregated. Like say you have 4 beads, 3 black and 1 white. And you non-blindly align all combinations of three beads. You'll have four combinations, three of which contain a white bead. So the probabilistic odds of any one combination of three beads containing a white bead is 75%. If a person picks three beads based on preference, another person can say that there's a 75% chance that those three beads will contain a white bead, iterated over enough picks. But the actual picking for all picks is fully determined by the current preference of the person picking the three beads.