We knew that the story of disgraced Grey’s Anatomy writer Elisabeth R. Finch was bad. But we had no idea just how horrible it really was until we screened Peacock’s three-episode Anatomy of Lies documentary (now streaming).

Over the course of the three hours, the limited series hits us with one whopper after another, foremost among them being the lie that Finch was treated for chondrosarcoma, the type of cancer that she gave Debbie Allen’s Catherine Fox on ABC’s long-running medical drama. To sell her hard-luck story, Finch — who on Tuesday issued another mea culpa on social media — shaved her head,...