Clooney has the distinction of being the only person nominated in the same year both for an acting award and Best Director, but for different films. When he won the Oscar for Best Supporting Actor for Syriana, he drew heavy criticism for giving Hollywood credit for the civil rights movement and AIDS awareness:
“And finally, I would say that, you know, we are a little bit out of touch in Hollywood every once in a while, I think. It’s probably a good thing. Uhm, we’re the ones who talk about AIDS when it was just being whispered. And we talked about civil rights when it wasn’t really popular. And we, uh, you know, we bring up subjects…we are the ones…this Academy, this group of people gave Hattie McDaniel an Oscar in 1939 when blacks were still sitting in the backs of theaters. I’m proud to be a part of this Academy. I’m proud to be part of this community. I’m proud to be out of touch. And I thank you so much for this.”
McDaniel actually was made to sit at the back of the auditorium near the kitchen at the Oscar banquet in which she won the award, and read a speech prepared by MGM in which she promised to be a credit to her race. The Academy didn't award another Oscar to a person of color for over twenty years after her win. As for Hollywood bringing the AIDS epidemic to the masses, the New York Times first reported on the disease in 1981 and Movieland didn't dramatize it until four years later with the touching TV drama An Early Frost. The first major theatrical release to tackle AIDS was 1993's Philadelphia, which gingerly tip-toed around the homosexual relationship between the characters played by Tom Hanks and Antonio Banderas and which Oscar nominated screenwriter and noted AIDS Activist Larry Kramer called "a heartbreakingly mediocre film. It's dishonest, it's often legally, medically and politically inaccurate, and it breaks my heart that I must say it's simply not good enough and I'd rather people not see it at all." Hollywood patted itself on the back for its mediocrity by awarding the Best Actor Oscar to Hanks in an absurdly overrated performance.
If you want to be technical about it, all-time Oscar champ Walt Disney was also nominated in six competitive categories. He won Oscars at various times for Best Feature Documentary, Best Short Subject Documentary, Best Live Action Short Subject, and Best Cartoon Short Subject. He was also nominated for producing a Best Picture nominee, Mary Poppins (1964). That's five categories, but from 1936-1956 the Academy divided the live action shorts into two different categories: One Reel and Two Reel. Disney won four of his Oscars in the Short Subject, Two Reel category (he was never nominated in the One Reel category), so if you want to distinguish that category from the Live Action Short Subject category, he shares the record with Clooney. We don't.