Sounds like a bit of a hyperbole, Blanket statements like 100% coverage, unit test per method are not too helpful, and it's important to understand the point

Sounds like a bit of a hyperbole, Blanket statements like 100% coverage, unit test per method are not too helpful, and it's important to understand the point where you will start to see diminishing returns with unit tests but that said well written unit tests with ~ 85-95 coverage by line free of conditional logic (use custom asserts) with meaningful test names/descriptions aren't exactly going to put you in league with beezlebub.