Philip Seymour Hoffman's tears in this scene were genuine. He later admitted he wasn't prepared for how emotional Tom Cruise became, and knowing Cruise had experienced something similar with his own father made the moment land that much harder.
The only film where I truly admired Tom Cruise. He was brilliant, outstanding. Magnolia is a masterpiece.
Cooper Hoffman: “A lot of people idolize their parents because they’re great parents. It’s a different thing to idolize your parent because you love their art.” (via @GQMagazine)