Actress Faye Dunaway thought co-presenter Warren Beatty was joking when he paused before showing her the envelope that should have contained the Oscar's best picture winner, she told Lester Holt on "NBC Nightly News."
Dunaway said she thought Beatty was stalling for effect.
She read "La La Land" as best picture winner rather than "Moonlight" after PwC partner Brian Cullinan mistakenly handed them the back-up envelope for Actress in a Leading Role instead of the envelope for Best Picture.
She read the movie's title on the card but didn't notice Emma Stone's name, Dunaway said.
She felt "completely stunned" and later felt guilty because she thought she could have done something to prevent the debacle.
Holt's interview with Dunaway will air Tuesday on the "Today" show.