Infamous episode which caught attention because of guest Joaquin Phoenix's weird appearance, only answering questions very limitedly and chewing gum, which he eventually stuck onto David Letterman's desk, and Letterman's constant mocking of this behavior. Since many felt that Phoenix's recent announcement to quit acting and his wish to focus on music in the future was nothing but an Andy Kaufman-like performance art hoax, it was also assumed that Phoenix and Letterman staged their whole conversation. It was admitted in September 2010 that Phoenix's appearance was indeed part of his assuming a fake persona for his performance in I'm Still Here (2010).
In September 2010 Casey Affleck told the New York Times that Joaquin Phoenix's announcement to retire from acting in order to become a rapper and his rather bizarre public appearances after that, which his visit on this show was one of, was part of an act he put up for the mockumentary I'm Still Here (2010).
Writer Bill Scheft claimed in a September 2010 interview that Letterman knew about the hoax beforehand and was playing along with it. But Letterman maintained in his interview with Phoenix on Joaquin Phoenix/Tom Jones/Huey the Dancing Macaw (2010) that he did not know about it beforehand and was just doing the best he could under the circumstances.