Having never read the books, I wouldn’t have known that the scene was to be anything more than as it was presented in the episode. Jaime and Cersei have, let’s call it, an extremely unique relationship. Changing that scene from a consensual act to one that is obviously non-consensual seems tricky enough.
And then those involved in the production opened their mouths. And, to the best of my knowledge, everyone quoted is a man. And then it got more and more awful.