After a classic he said, she said -- albeit, the he here is Warren Beatty and the she is newly Oscar-minted Emma Stone -- it turns out both were correct: Beatty was indeed given Stone's Best Actress envelope to read off instead of Best Picture, and she did have her winning Best Actress envelope with her afterward. Because there were two sets of identical envelopes.
Now, PricewaterhouseCoopers, the accounting firm that oversees Oscars' voting, has confirmed to ET exactly how Beatty and Faye Dunaway ended up with the wrong envelope: one set of envelopes was stationed on each side of the stage, manned by two PwC reps, Martha Ruiz and Brian Cullinan.
Stone's Best Actress envelope came from the side of the stage manned by Ruiz, New York Times clarifies, and when it came time for Beatty to receive the Best Picture envelope on the opposite side of the stage, he was given the duplicate envelope by Cullinan.
As for why the wrong envelope was given, it may have been as simple as the color scheme:
"The envelopes containing the winner's names were redesigned this year, and they featured red paper with gold lettering that specifies the award. Last year’s envelopes featured gold paper and red lettering, which may have been more legible. The Academy of Motion Picture Arts and Sciences, not PricewaterhouseCoopers, is responsible for the design and procurement of the envelopes."
"After Mr. Cullinan and Ms. Ruiz realized that the wrong winner had been announced, they notified the stage manager, which set in motion a chaotic scene watched by the celebrity crowd in attendance and tens of millions of viewers on television," the New York Times reports.
PricewaterhouseCoopers previously apologized for the on-air mix-up, stating, ""We sincerely apologize to Moonlight, La La Land, Warren Beatty, Faye Dunaway, and Oscar viewers for the error that was made during the award announcement for Best Picture."
"I've gone through this so much: They call a name, they don't call a name. It is what it is," he told ET at the Governors Ball. "You get over it...Like everyone else, I was applauding. I was celebrating the win."