Joanna: "Do you have anything to tell me about the night she died? Like did you punch her in the face and kill her?"
Joanna: "Actually I have to go to the bathroom."
That's our girl. So she chills out for a second in the bathroom of the place, trying to come up with even more subtle things to get Julian talking about whether or not he killed his sister and when she comes out... he's gone!
...Just kidding, he's on the veranda. That was close.
Julian: "Okay I maybe punched Vivian in the face."
Joanna: "I'm going to just have a seat and drink a lot more, then."
Julian: "You sure are dropping a lot of hints lately about how you're going to 'bring down the company' and my drug 'kills Thai cancer patients,' but I wish you'd be a little less vague."
Vivian: "I don't know that that's possible. But I will tell you I am kidnapping our little sister and running away the second I bring this family down."
Julian: "You junkie weirdo. I am so sure you could pull anything like that off."
Vivian: "Yeah, well, if Mom were alive she would hate you. You're a fraud and furthermore you never accomplished anything without Dad's filthy fingerprints all over it."
Which is when he punched her and it's more clear in the acting, but it's still pretty clear just thinking about the dialogue: Don't hit a lady. Don't hit a pregnant lady, for sure. But she had to know that was a major button to push, right? I mean, she was kinda goin' for it.
Vivian, from the ground: "What, Julian? You wanna beat me to death and throw me in the river?"
Julian: "Uh, no? That's insane?"
Vivian: "Because you're not man enough to do it!"
Then she runs off into the night. I don't know Vivian very well, but she does seem very like a trainwreck. Especially considering that this is her having supposedly gotten her act together.
Julian: "I got in my car and chased her to apologize, but then she ran across the highway like a freak, so I lost her. Went home."
Julian runs off to go cry or do some lines or whatever, while Joanna just loudly voices her hopes that the guys in the FBI van running her wire heard that whole non-confession, I guess because it was rough to listen to.
Joanna: "So he fully told me he punched her out of nowhere. I guess the rest of the alibi..."