Joan Rivers appeared on Access Hollywood Tuesday to explain why she walked out on CNN anchor Fredericka Whitfield mid-interview over the weekend. "Fifty years in the business, this is the first time I've ever walked off," she declared. "You've gotta understand -- when you interview someone, it's not an interrogation. And [Fredericka] was going at me, like, 'Why do you say this?' and 'Why do you say that?' It's like, you don't say to the Olsen twins, 'What's your favorite place to vomit?'" The 81-year-old comedian continued, "It was just [that] the questions were just coming out so negatively, and I found myself defending myself. And I thought, 'I'm a comedian!'" The interview in question made headlines Saturday after Whitfield asked Rivers why she wore fur on the cover of her new book and Rivers responded by telling her to shut up and storming off the set.