This author probably doesn’t account for how the scientific advances of the Medieval Renaissance were brought to a screeching halt by the plague.
Who knows how far our understanding of the natural sciences would have advanced had the major players not been killed off.
Not sure what you mean, the Plague (which were a series of outbreaks, killed a quarter of Europe) resulted in an explosion of capitalism and implosion of feudal relationships, more general literacy, and the Renaissance.