PricewaterhouseCoopers representatives Martha Ruiz and Brian Cullinan attend the 89th Academy Awards on Feb. 26, 2017. (Photo: Christopher Polk, Getty Images) 
 
 The accountants did it? 
 
 We all watched in shock as it happened. Now we know exactly what happened. 
 
 PricewaterhouseCoopers, which has handled the accounting for the Academy Awards since 1934, early Monday apologized for giving the wrong envelope to presenters Warren Beatty and Faye Dunaway before the two actors erroneously announced La La Land as best picture at Sunday night's Oscars. In actuality, Moonlight won the top prize. 
 
 In Beatty's hand was a spare best actress envelope. Emma Stone had already been given her winning envelope, but two sets are printed, one for each of the two PwC representatives who wait in the wings to distribute the envelopes to presenters. 
 
 "At the end of the day, we made a human error," Tim Ryan, U.S. chairman and senior partner of PwC told USA TODAY on Monday. "We made a mistake. What happened was, our partner on the left side of the stage, Brian Cullinan, he handed the wrong envelope to Warren Beatty. And then the second we realized that, we notified the appropriate parties and corrected the mistake." 
 
 But several speeches by La La Land producers had already been given, and celebrating was underway. 
 
 "We apologize to the cast of La La Land for having to have made those speeches in the time that it took to (correct it)," says Ryan. "Immediately when it was announced, again, because of our mistake, both our partners who knew who the winner was — and they’re the only two who know — they realized the mistake had been made and they began to notify the appropriate people. 
 
 "It was a little chaotic and just took time to get out onstage and let people know that the mistake was made. And unfortunately that took enough time to get through two-and-a-half acceptance speeches." 
 
 It's puzzling because the Oscar process — counting the votes, determining the winners, filling the envelopes, packing two briefcases, toting them to the ceremony, handing the envelopes to presenters — is long-established. 
 
 Prior to the Oscars, Cullinan, a managing partner at PwC, and Martha Ruiz, a tax partner at PwC, described how the winning envelopes are handled. 
 
 As 'La La Land' filmmakers accept the award, PricewaterhouseCoopers' Brian Cullinan, holding red envelope, and Martha Ruiz, in red dress, and a stage manager examine the envelope with the wrong winner for best picture, which was 'Moonlight.' (Photo: Chris Pizzello, Invision/AP) 
 
 After voting closes a week before the live Oscars telecast, accountants start tabulating, which takes about three days. Secrecy and accuracy are the watchwords. "While we have a team counting the ballots, none of our team members see more than a portion of the ballots in any category. The final tabulation of the winners is only done by the two of us," Cullinan and Ruiz wrote at The Huffington Post. 
 
 They check and recheck, identify the names with the highest number of votes in each category, and insert two sets of the cards declaring the winners into sealed envelopes, which are secured in a secret location until they are brought to the show. 
 
 "At the event, we are both backstage to hand the envelopes to the presenters. We also memorize Every. Single. Winner. In. Every. Single. Category. The winners’ names are not typed into a computer or written down, to avoid potential lost slips of paper or breaches of security," Cullinan and Ruiz explained. 
 
 CLOSE USA TODAY's Bryan Alexander and Carly Mallenbaum give their observations on the Oscar best picture mixup. Robert Hanashiro, USA TODAY 
 
 Here's where it gets even more fascinating, considering Sunday's flub: It could only have been a PricewaterhouseCoopers rep who gave the wrong envelope to Beatty and Dunaway. 
 
 Backstage, Cullinan and Ruiz "hand each envelope directly to the presenter in each category. We are positioned on either side of the stage, so we can hand envelopes from stage right or stage left." 
 
 Ryan says he has apologized to the Academy of Motion Picture Arts and Sciences and is contacting the producers of La La Land and Moonlight. 
 
 "I have spoken with the Academy and expressed our apologies and accountability, and I am in the process of reaching out to the other affected parties," said the PwC chairman. "That has not happened yet, but I am in the process of doing that." 
 
 But not to worry, says Anthony Sabino, a law professor at St. John’s University’s Peter J. Tobin College of Business. It was a "black eye" for PwC, but black eyes heal. He predicts no long-lasting effects. 
 
 "While all the facts are not in yet, it would appear to be simple human error," Sabino says. "After decades of flawless performance, it was bound to happen eventually. For an event as complex and as secretive as the Academy Awards, PwC's sterling record still stands out.” 
 
 Read or Share this story: http://usat.ly/2lNl5A5 ||||| Here’s the elevator pitch: “The Social Network” meets “The Oscar” meets “The Accountant.” 
 
 The worst mix-up in the history of the Academy Awards resulted from a disastrous collision of Hollywood, social media and an accounting firm. 
 
 A managing partner at PricewaterhouseCoopers LLP mistakenly handed presenter Warren Beatty an envelope on Sunday... ||||| UPDATED: In his fourth year of handling envelopes for the winners of the Academy Awards, PricewaterhouseCoopers partner Brian Cullinan picked a bad time for a miscue — pulling the envelope for what was supposed to be the best picture winner from the wrong pile. 
 
 As a result, presenter Warren Beatty carried the wrong envelope Sunday night, meaning that his on-stage partner, Faye Dunaway, announced “La La Land” was the winner of the night’s top prize. “Moonlight” was actually the best picture winner. 
 
 Tim Ryan, the accounting firm’s U.S. chairman and senior partner, offered an explanation Monday of the unprecedented miscue, along with his profuse apologies to the Motion Picture Academy and to the filmmakers behind the two movies. 
 
 “We clearly made a mistake and once the mistake was made we corrected it and owned up to it,” said Ryan, attributing the foul-up to “human error.” 
 
 Ryan said he had spoken to Cullinan about the episode at length. “He feels very, very terrible and horrible. He is very upset about this mistake. And as a firm, given that he is a partner of our firm, it is also my mistake and our mistake and we all feel very bad.” 
 
 Related Trump: Oscars Best Picture Flub Occurred Because Show ‘Focused So Hard’ on Him 
 
 Cullinan was positioned stage left during the evening. His colleague, Martha Ruiz, stood in the wings, stage right, Ryan said. Each had a pile of envelopes for presenters entering from their side of the stage and then a pile of “backup” envelopes for the presenters entering from the other side of the stage at the Dolby Theatre. 
 
 Cullinan pulled the lead actress envelope that was in the “backup” pile and handed it to Beatty. “There’s a stack for the backups and the ones that are not the backups and he took from the wrong stack,” Ryan explained. 
 
 Beatty hesitated twice after opening the envelope, apparently confused when he saw both the name of lead actress winner Emma Stone and “La La Land.” Not understanding Beatty’s hesitation, Dunaway said: “You’re impossible. C’mon.” Beatty then showed her the card and Dunaway announced: “La La Land.” 
 
 Asked if Beatty and Dunaway could have recognized the error, Ryan said: “No, look, it’s our job, not theirs.” 
 
 The PwC chairman said that both Cullinan and Ruiz, who had memorized all of the winners, as per company procedure, realized instantly that an error had been made. “Martha … immediately recognized that was not who won,” Ryan said. “She opened up her backup envelope to confirm her memory.” Cullinan immediately told members of the production team of the error, Ryan said. 
 
 Procedure for such a mistake calls for the PwC employees to then take the stage, along with members of the production staff, to correct the error, Ryan said. He did not know why it took more than two minutes for the correction to be made, with “La La Land” producer Jordan Horowitz delivering the news to the world that “Moonlight” was the real best picture winner. 
 
 “This is the first time in over 80 years that there has ever been a problem and again we are very disappointed in ourselves,” Ryan said. “I have reached out to the Academy and shared with them that we take full responsibility that Brian had made the mistake and the firm takes responsibility for that.” 
 
 Ryan said he was not focused now on whether the flub would hurt the firm’s relationship with the Academy or its prospects of returning for another year of counting the ballots. “I expect us to get something like this right and our focus right now is just on making sure the academy and the rest of the folks know that and the rest will play out,” Ryan said. “We are very proud of being associated with the Academy Awards. It’s good for our brand. It’s good for our people. So while I am concerned I hope we will be judged on how quickly we reacted and owned up to the issue.” 
 
 Watch the moment unfold below: ||||| Pricewaterhouse Employee Accountant is Oscar Envelope Culprit 
 
 Pricewaterhouse Accountant is the Oscar Envelope Culprit 
 
 Exclusive Details 
 
 This is the guy who we're told is responsible for the biggest screwup in Oscar history ... the guy who handed Warren Beatty the wrong envelope. 
 
 His name -- Brian Cullinan -- an accountant at Pricewaterhouse. He's a veteran ... 30 years at the accounting firm. 
 
 Here's the thing ... Brian was supposed to discard the spare Best Actress envelope and hand Warren Best Picture. 
 
 As for why ... we know this. Brian was tweeting like crazy during the ceremony, posting photos ... so he may have been distracted. Brian has since deleted the tweets, but one was a pic of Emma Stone with her Oscar. If it was tweeted right after her win, that's exactly when Brian should've been prepping for the next category ... Best Picture. 
 
 No word on whether discipline is in store. 
 
 We're told the firm is issuing an apology to all concerned.
– The Wall Street Journal may have figured out how exactly the biggest flub in Oscars history happened Sunday night. As the paper explains, Brian Cullinan and Martha Ruiz are the two PwC partners who stand at opposite ends of the Academy Awards stage with the envelopes containing the winners, ready to hand said envelopes to the appropriate presenters—and both hold a full set of envelopes, because they don't know for certain in advance which side of the stage presenters will walk in from. Immediately prior to the Best Picture award being presented, Ruiz had handed the Best Actress envelope to presenter Leonardo DiCaprio, who then read it onstage and presented the Oscar to Emma Stone for La La Land, sources tell the Journal. Cullinan, who still had an identical Best Actress envelope in his stack, then apparently handed that envelope instead of the Best Picture envelope to presenter Warren Beatty. About three minutes before Beatty and co-presenter Faye Dunaway walked onstage to present the Best Picture award, Cullinan tweeted a photo of Stone holding her Oscar along with the caption, "Best Actress Emma Stone backstage! #PWC." The Journal says Cullinan had tweeted other photos during the awards show, but all of them, including the photo of Stone, have since been removed from his Twitter feed. (The Journal has a screenshot of the Stone tweet.) "At the end of the day, we made a human error," the US chairman and senior partner of PwC tells USA Today. He acknowledges Cullinan handed the wrong envelope to Beatty, though no mention was made of the tweeting, which TMZ says might have "distracted" Cullinan. The senior partner also tells Variety that Cullinan "feels very, very terrible and horrible. He is very upset about this mistake. And it is also my mistake, our mistake, and we all feel very bad."