The statement added: "The presenters had mistakenly been given the wrong category envelope and when discovered, was immediately corrected. We are currently investigating how this could have happened, and deeply regret that this occurred. We appreciate the grace with which the nominees, the Academy, ABC, and Jimmy Kimmel handled the situation."
In years past, the firm has provided two sets of winners' envelopes in briefcases that are sent to the Dolby Theatre, one briefcase for either side of the stage.
In what was was supposed to just be a memorable movie reunion, Warren Beatty and Faye Dunaway ended up fumbling the presentation of best picture, as they were apparently holding the best actress envelope instead.
Not only did Dunaway read off La La Land as the best picture winner, the confusion wasn't fixed until after several members of the Lionsgate movie's team had already spoken. "I opened the envelope and it said 'Emma Stone, La La Land.' That's why I looked at Faye, and at you. I wasn't trying to be funny," Beatty clarified, laughing nervously.
"This is very unfortunate, what happened. Personally, I blame Steve Harvey for this," emcee Jimmy Kimmel said, trying to salvage the moment with a joke about how Harvey had announced the wrong winner of the "Miss Universe" pageant on live TV in 2015. However, this mistake was far worse.
La La Land producer Jordan Horowitz had to take a ballot and show the TV audience that, in fact, it said Moonlight. "I was ecstatic, it was amazing. I thought we won an Oscar," Horowitz recalled to The Hollywood Reporter. "Some guys in headsets started buzzing around. It became clear that was something wrong. They took the envelope I had. It said 'Emma Stone, La La Land' on it."
He added: "It was clear that there was something wrong. We started looking for the best picture envelope. Nobody knew where it was. Then it appeared, they opened it next to me and it said 'Moonlight.'"
PwC has had Brian Cullinan and Martha Ruiz as co-ballot leaders overseeing the process for several years. The company touted that the ballot briefcases had made stops in 11 cities across the U.S. before making its way to Hollywood for the big day.
Backstage, Moonlight director Barry Jenkins was asked to explain the moment. "No explanation; things just happen," he said. "I will say I saw two cards. I wanted to see the card, and Warren refused to show the card to anybody before he showed it to me. He said, 'Barry Jenkins has to see the card. He needs to know.'"
With the top honor yanked away from the frontrunner, La La Land ended the evening with six wins. Emma Stone, who claimed best actress, was cordial when asked about the confusion by reporters.
"I f—ing love Moonlight," she said. "Of course it was an amazing thing to hear them say La La Land — we would have loved best picture, but we're so happy for Moonlight."
Meanwhile, at the Governors Ball, Dunaway wasn't as gregarious about the moment. The presenter told THR, "No, I'm not going to speak about it."
Rebecca Sun, Mia Galuppo and Scott Feinberg contributed to this article.