Which members of the production crew are responsible for the envelopes containing Oscar winners?

There are two envelopes for each category.

Two people, Martha Ruiz and Brian Cullinan, count the votes and know the winners in advance. Each has a full set of envelopes containing cards with the winners' names - just in case something happens to the other set.

Those people - from accountancy firm PwC - stand on either side of the Oscars stage and hand the envelopes to the award presenters just before they step on stage.

This article shares some thoughts on this.

The Academy takes the process of tabulating winners and then keeping their identities a secret very seriously. They entrust it to the accounting firm PricewaterhouseCoopers. Since 2005, the same two men have been in charge of handling the final tallies and guarding the winners’ names: Rick Rosas and Brad Oltmanns(Correction: now Martha Ruiz and Brian Cullinan) Also known as the “men with the briefcases on the red carpet,” their responsibilities are quite real and not mere ceremony.

The designated two people in charge then assemble the final count. Winners are written on cards in a secret location and then placed in the sealed Oscars envelopes, which are then put under tight lock and key until the day of the ceremony. As awards presenters enter the stage, they receive the sealed envelopes and legitimately discover the winner’s identity for the first time as they tear open the seal. As such, their surprises are genuine, as are the actual winners they announce.

(correction and emphasis mine)

PricewaterhouseCoopers, the company responsible for the Academy voting, said in a statement:

"We sincerely apologise to Moonlight, La La Land, Warren Beatty, Faye Dunaway and Oscar viewers for the error that was made during the award announcement for Best Picture.

"The presenters had mistakenly been given the wrong category envelope and when discovered, was immediately corrected. We are currently investigating how this could have happened, and deeply regret that this occurred.

The production crew plays no part in handing out the envelopes. The envelopes containing the winners are handed out to the presenter(s) by two partners of the accounting firm PricewaterhouseCoopers (PwC).

For more than eight decades, PwC has been overseeing the Oscars balloting process, which involves collecting ballots, tallying the votes, and then delivering sealed envelopes bearing the winners’ names.

The process of the handling of the envelopes are as follows:

• Two balloting leaders are selected by PwC
• The two balloting leaders are shown the winners in each category so that they can memorize them after the results are tallied.
• On the night of the ceremony, each leader carries their own briefcase containing the sealed envelopes with the winners into the theater.

• Once inside, the two ballot leaders station themselves on opposite sides of the stage throughout the ceremony and one of them hands the envelopes to the presenters, depending on which side of the stage the presenters enter from.

IN REGARDS TO THE WRONG BEST PICTURE BEING ANNOUNCED:

Tim Ryan, U.S. chairman and senior partner of PwC told USA Today:

What happened was, our partner on the left side of the stage, Brian Cullinan, he handed the wrong envelope to Warren Beatty.

The best-actress envelope Cullinan wrongly handed to Beatty was a duplicate, according to the Journal. Ruiz was the one who, moments before Cullinan’s error, had correctly handed her copy of the best-actress envelope to Leonardo DiCaprio who presented that award to Stone.

The accounting firm PwC (PricewaterhouseCoopers) is in charge of the the ballot, counting and preparing the envelopes to be handed out later.

As per the official article,

Brian Cullinan and Martha Ruiz are partners at the professional services firm PricewaterhouseCoopers. They are also the only two people who know the list of Oscar winners before the rest of the world

https://medium.com/art-science/what-it-feels-like-to-count-oscar-votes-f89a38efdf1c