In what may well become the most famous tweet that went wrong, a managing partner at PricewaterhouseCoopers LLP has been discovered to have given the wrong envelope to Warren Beatty on Oscar night as a possible result of being distracted by tweeting a picture of Oscar-winning actress Emma Stone only moments before.

The Wall Street Journal reports that Brian Cullinan, one of two PwC partners holding envelopes with the names of Oscar winners, tweeted “Best Actress Emma Stone backstage! #PWC” along with a photo of the actress at 9:05 p.m. Pacific time, roughly three minutes before Warren Beatty and Faye Dunaway walked on stage, where they announced the wrong Best Picture.

Cullinan handed Beatty the envelope, unaware that it was the wrong one, duplicate copy of the envelope containing Ms. Stone’s name as best actress for La La Land. That prompted Dunaway to read La La Land as best picture.

Cullinan later deleted the tweet, but WSJ spotted it. Cullinan had posted other photos on Twitter during the Oscars as well.

PWC issued a statement saying, “We are currently investigating how this could have happened, and deeply regret that this occurred.”

After Cullinan handed the correct envelope to Beatty, Jordan Horowitz, the show’s producer, grabbed the envelope from the hosts and declared the real winner, stating, "This is not a joke; Moonlight is Best Picture."

PwC partners Cullinan and Martha Ruiz are the only people who are privy to who the winners are; thus two minutes after Dunaway wrongly announced La La Land as best picture instead of Moonlight, they rushed over to correct the mistake. Unfortunately, two La La Land producers had already given their acceptance speeches.

Cullinan and Ruiz were positioned on opposite sides backstage at the Dolby Theatre in Hollywood; they both had a full set of envelopes containing the winners in all 24 Oscar categories, because it is not totally clear which side of the stage presenters will enter from. Ruiz gave the best-actress envelope to presenter Leonardo DiCaprio, which meant Cullinan had the extra envelope for that category, which he mistakenly gave to Beatty.

The Journal noted that Cullinan’s Twitter bio illumines him as “Counting Oscar ballots and keeping secrets.” This was his fourth year handling the envelopes.