Ray Richmond contributes to Deadline’s TCA coverage.

Actor Liev Schreiber, who plays the lead in the Showtime drama series Ray Donovan, couldn’t be listed in the cast of the HBO film Clear History starring Larry David that premieres August 10. David admitted as much while responding to a TCA panel question about why Schreiber wasn’t in the credits despite having a good-sized role in the comedy as a Russian heavy. “That was a Showtime issue,” David said. “Kind of a Showtime-HBO thing.” This is not the first time HBO has taken issue with Schreiber’s role in Ray Donovan on rival Showtime. When the actor was first cast in the pilot, HBO threatened to drop him as the exclusive voice of its sports division but ultimately re-signed him.

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David was less forthcoming when it came to a question about whether he might do another season of Curb Your Enthusiasm for the network. “I don’t know,” he said. “I haven’t decided. I couldn’t say. … Ask me in six months.” This is, of course, business as usual in Larry David world. It’s well known that he has carte blanche to do as many seasons of Curb as he wants, but he’s always reluctant to commit. In fact, he decided to do Clear History — which he stars in and co-wrote for director Greg Mottola. “I will say this,” David added. “I was thinking of doing another season of Curb or doing a movie, and I thought perhaps it’s time I tried something else.” However, David was far more playful than defensive during a Clear History Q&A beside Mottola.The film, performed improvisationally using only an outline (much like Curb), stars David as a guy whose life goes into the toilet when he gives up 10% of the shares in an electric car company just before it turns into a multibillion-dollar smash. The all-star cast includes Jon Hamm, Kate Hudson, Bill Hader, Michael Keaton, Danny McBride, Eva Mendes and J.B. Smoove.

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One critic wanted to know if David himself ever came close to leaving $1 billion on the table by, say, quitting Seinfeld early on. “I did quit a couple of times,” he admitted, “but the show was barely off the ground at that point — and it wouldn’t have been as good without me, of course.” One of the in-jokes in the HBO original film surrounds David’s character’s obsession with a painting called a “Plepler.” Any similarity between that and HBO CEO Richard Plepler was entirely coincidental, right? “I just thought Plepler was a funny name,” he insisted. “I wanted to get a chuckle when I said it. I mean, where are there two ‘L’s’ in there?” And he had no trouble getting it past legal? “Not a bit,” David replied. Later it was asked if, after having such a great experience making Clear History, he might want to now go the Woody Allen route and make a new film every year. “Not a chance, Woody is superman,” he said. “Maybe every six or seven or eight years. We’ll see how it goes.”