Transcript for Wrong movie announced for best picture at the Oscars
Next here on a Monday night of that surprise ending at the Oscars the wrong movie announced for the highest honor best picture. Chaos on the stage when officials stepped forward to say there'd been a mistake it wasn't -- land but instead moonlight winning the honor. The audience you can see right there stunned both in the theater in so many viewer at home. ABC's Tommy Thomas tonight with new reporting here on how this happened. And the Academy Award tens of. Millions all round the world watching Warren Beatty. But even he seemed unsure or best picture fate go to waste it needed to they of the biggest prize of the night. Lot of loud laugh. Start flying Gosling and it was stone. Along with the film's producers taking the stage thank you to my parents put three minutes later after a few speeches solidly behind them you see the commotion. Oh plot twist no one saw coming. Lawler Lynn produced recorded Horowitz taking the Mike and revealing this if there's a mistake. Moonlight you guys won best picture. Actionable winter the fields you confused at first still in the big button in cheers director Billy Jenkins. Real very clearly even in my dreams this could not be true. But Alex graves on dumb when it could this is true oh my goodness. One big snafu clue was on stage the entire time. Look closely at the global look at big east hand. Actress in a leading role not this picture they can. Explaining to the audience I opened the envelope. And it said. Emma Stone wallow that. That's why I took such a long look at today and that you. I wasn't trying to be funny. So. How does happen. That eight years accountant from WC has apparently did ballots. Q accountants bringing two sets of winning global Lopes in matching briefcases to the ceremony. Each station on either side of the stage. But at the end of the show accountant Brian Cohen in somehow hitting big the second copy of it was told best actress well below. You'll look for best film the libel award. PWC putting out this statement overnight we sincerely apologize to moonlight La La land Warren Beatty. They got away and and Oscar viewers for the era that was made during the award announcement for best picture. The presenters had mistakenly been given the wrong category all below and when discovered was immediately corrected. It's not the first time back in 1960 or sick days it was handed the ball all below. They gave me the wrong envelope. Way to the NAACP hears about this. As producers makes up. Best actress Emma Stone tablet or a new robot backstage movie likes victory was will be served and so beyond exit from the man I think that is. One of the greatest albums of all times are Herschel alt least seen here backstage withdrawing Gosling. Raising the crew from law law land for graciously handling the mix up at the guy needed to hear them say it multiple times and movie grows up. And I just I salute local all of those numbers. Not since 1964 that clip from Sammy Davis junior we love scene that Tom in the meantime a you're with us from LA tonight atop the account who gave the wrong envelope to Warren Beatty. Apparently sent out a tweet and then deleted it. That's right David we want to put that tweet up on the screen right now which shows Emma Stone holding that Oscar statue wit that caption reads best actress Emma Stone. Backstage hash tag PW see it came from the account of trying Cohen in that account in question and it was posted. What around the time that he gave that all below the wrong all below. To the two legendary actors Warren Beatty and Faye Dunaway right when they walked out there on stage they'll many question tonight whether. This account was distracted and that's what led to the big air David. Now questions about social media and confusion Tommy honest witness from LA tonight Tom thanks as always.
This transcript has been automatically generated and may not be 100% accurate.