What the author seems to miss is that before he could describe decay pathways he had to learn what an isotope was. We shouldn't mistake the simplestory-tellers

What the author seems to miss is that before he could describe decay pathways he had to learn what an isotope was. We shouldn't mistake the simplestory-tellers for tenured scholars - their job is not to render dissertation. It is to provide insight appropriate to the audience's level of understanding.