LOS ANGELES - Moments before he handed out the wrong envelope in one of the worst gaffes in Oscar history, PwC accountant Brian Cullinan tweeted a behind-the-scenes photo of winner Emma Stone holding her statuette. "Best Actress Emma Stone backstage!" the tweet read.

It's one potential clue in the whodunit that Sunday's ceremony became after presenters Faye Dunaway and Warren Beatty mistakenly proclaimed "La La Land" as the best-picture winner instead of "Moonlight."

Cullinan was one of two accountants for PwC, formerly Price Waterhouse Coopers, tasked with doling out the envelopes containing winners' names to the presenters. But the envelope that Cullinan gave to Dunaway and Beatty was a duplicate of the previously announced win for Stone, not for best picture.

PwC declined comment Monday about Cullinan's social-media use may have distracted him.