According to TMZ, Brian Cullinan, an accountant at Price Waterhouse is responsible for the biggest screwup in Oscar history... he’s the guy who handed Warren Beatty the wrong envelope.
Cullinan is a veteran. He’s spent 30 years at the accounting firm.
He was supposed to discard the spare Best Actress envelope and over Best Picture. He was tweeting like crazy during the ceremony, so he may have been distracted. One tweet was a pic of Emma Stone with her Oscar. If it was tweeted right after her win, that's when he should've been prepping for Best Picture.
No word on whether discipline is in store for the accountant.
Source: TMZ