Unfortunately, the presenters only realised there was a problem after it was too late.
The best-picture nominees, with their number of nominations, are "The Shape of Water" (13), "Dunkirk" (8), "Three Billboards Outside Ebbing, Missouri" (7), "Darkest Hour" (6), "Phantom Thread" (6), "Lady Bird" (5), "Get Out" (4), "Call Me by Your Name" (4) and "The Post" (2).
As he showed her the envelope, she took it from him before revealing that La La Land was the victor.
Odd Thoughts: Kids keep gun control conversation on point
There wasn't any expectation that they would sway people who live off NRA campaign funds, but that's how movements start. Even the writers to Sound Off are beginning to sound violent in their hatred of people with opposite political views.
But the biggest change became quickly apparent Sunday as Viola Davis presented the award for best supporting actor.
And Beatty/ Dunaway's return isn't the only presenter shake-up this year, with an old tradition - whoever won Best Actor the previous year presenting Best Actress - falling by the wayside after last year's male victor Casey Affleck declined to take part in the ceremony.
Dunaway went on to say that last year's error had been on her mind ever since. But an accountant from PricewaterhouseCoopers, who had all of the winners memorized, was sitting in the control room with producers just in case something went wrong.
If at first you don't succeed, try again!
"Obviously mistakes happen", Todd tells USA TODAY about the humorous look back to past year.
Comediennes Haddish and Rudolph co-presented the awards for animated and live-action short films and they were hilarious.