Gibson has rarely been seen in public since the controversial remarks he made to police during his high-profile, drunken-driving arrest last year.
But the "Apocalypto" and "Braveheart" director seemed relaxed as he told Extra he was eager to see Washington and Crowe's new film, which was directed by Ridley Scott.
"These three big players here, they're all friends of mine," Gibson said. "I'm an admirer of their work individually. I just want to see what they can cook up together, you know."
Asked if he has any future plans to work with them, Gibson replied, "Maybe, maybe I'd like to direct one with all of them in it, including Ridley."
"I was surprised to see him here, but glad to see him here!" Washington told Extra.