Sleuths on the internet have found that Warren Beatty was holding the wrong envelope onstage when he was presenting the best picture award. His envelope appears to say "actress in a leading role" on the outside:
That's what led to co-presenter Faye Dunaway seeing Emma Stone's best actress card for "La La Land" in the envelope, and incorrectly announcing the film as the best picture winner.
But Emma Stone mentioned that she was holding onto her already-opened best actress card that was used when her name was announced.
So how is that possible? Apparently there are "two sets" of envelopes for each winner, according to a BBC interview with Martha Ruiz, a partner at accounting firm PriceWaterhouseCoopers, which counts the votes.
USA Today confirms this account in its report from backstage: "The real drama kicks in when La La Land filmmakers take the stage to accept best picture.The accountant from PriceWaterhouseCoopers jumps up and says, 'He (presenter Warren Beatty) took the wrong envelope!' and goes running onstage."
A big question is: What if Beatty had instead grabbed the "actor in a leading role" envelope, with Casey Affleck's name on it? Then Dunaway might have announced the best picture winner as his film, "Manchester by the Sea," an extreme long shot - and everyone would have really been surprised.
But it fell to Jordan Horowitz, a producer of "La La Land," to clear up the Oscars mistake. He had been the one to tell a stunned audience that, actually, "Moonlight" won.
Horowitz gave play-by-play after the ceremony on E!, explaining that he had taken the envelope after the winner was announced and held the card as he gave his acceptance speech.
"There was a guy, a stagehand guy, who started kind of buzzing around, looking for the envelope," Horowitz said.
Eventually, the envelope was found. He "opened it, and it said 'Emma Stone, La La Land' on it," Horowitz said. "At that moment, it was clear there was a problem. They eventually found the best picture envelope."
Twitter is having a field day following the most bizarre flub in Oscars history, when "La La Land" was mistakenly announced as best picture winner before the award was correctly given to the real winner, "Moonlight."
The mix-up was an odd but thrilling cap to a more-than-three-hour broadcast. Adding to the tension was the fact that "Moonlight" and "La La Land," long considered the favourites in the best picture category, couldn't be more different. "La La Land" is an extravagant musical about Hollywood. "Moonlight" is a coming-of-age story that grapples with weightier issues including race, poverty, sexuality and drug addiction.
In the immediate aftermath, it was clear that no one knew exactly what happened, but that didn't stop the Internet from trying to sort it all out. Here are some of the best reactions, which ranged from utter disbelief to more humorous takes.
Here's Ryan Gosling looking surprised, but also amused.
Some expressed sympathy for the casts and crews of both films and also Warren Beatty, who presented the award with Faye Dunaway.
At first, it looked like Beatty was playfully drawing out the best picture announcement. He took a long look at the card before handing it over to Dunaway to read the winner. But, as he later explained, he was genuinely confused by the envelope, which read "Emma Stone, 'La La Land.' (Moments earlier, Stone had accepted the best actress award for the musical). That's why I took such a long look at Faye," Beatty told the audience. "I wasn't trying to be funny,"
Steve Harvey jokes
Harvey famously botched announcing the winner at the 2015 Miss Universe pageant, and the comparisons came rolling in.
Some were re-living the election...
...or at least, their desired outcome.
As Harvey knows well, there will be rumors that this happened on purpose.