I have to say I'm surprised and disappointed by the lack of discussion about what David did to Syd and how that effects the nature of the show and his character. He raped Syd. He robbed her of her agency by suppressing her memories of her terror she felt about him and, as she said, he drugged her and had sex with her. There may have not been any screaming, but there was unequivocally no consent.
The A.V. Club's Alex McLevy best expresses why this is so damaging for the show and the character of David:
If you’re halfway through watching Out Of Africa, you know you’re not going to have a sudden smash cut to a pornographic, throbbing sex scene between Robert Redford, Meryl Streep, and another person, because that would violate a basic understanding of the world that’s been established, what a mainstream movie provides, and also how these characters would behave. Similarly, Legion has established that there are many facets to David, but despite the depictions of a malevolent David, or a homeless crazy David, or even the fears of our primary David about the violence he’s capable of inflicting (something that wasn’t even introduced until the last couple of episodes), we had been given a fundamentally good person. Naive, even, in his sincere belief in true love, admirable in his loyalty to his friends, and—above all—steadfast in his refusal to accept evil or unhappiness as the outcome. When Syd brooded over their likely unhappy ending, David was the one to say he believed in a better one. Even when he was torturing Oliver last week, we may not have liked it, but we understood doing something bad to achieve something good. He was trying to save Syd.
Transforming David from a fundamentally decent person with a troubled mind into someone capable of committing sexual assault in the course of a single episode is the needle scratch on the record player. It’s the porn scene in the middle of Out Of Africa. It’s edgy and unpredictable, but that doesn’t make it good. It changes the show on a fundamental level—and more than that, it pulls the rug out from under its viewers, scorning them for thinking they were watching one kind of show when in fact they were watching a very different one. It’s one thing to have a show’s characters lie to us. It’s quite another when a show lies to its audience.
Like I said in my own review, I hope the show doesn't shy away what David did to Syd in the next season and properly analysis what happened.