As previously reported, WWE referee Chad Patton, who served as the in-ring official for the Brock Lesnar vs. Undertaker match at WrestleMania XXX, was not aware that Lesnar was going over in the bout. As noted, he was actually told that Undertaker was supposed to win.
As far as who else in the company knew ahead of time, that is hard to say. We can say for certain that Vince McMahon, Brock Lesnar, Undertaker, Paul Heyman, and likely Triple H and Stephanie McMahon all knew, but beyond that, it''s difficult to say.
On the actual script for the show, no finish was listed for the Lesnar-Undertaker match. However, that wasn't unusual, as other matches on the card did not have a finish listed on the script as well.
According to reports, none of the agents who worked the show were aware that Undertaker was going to lose.
It should be noted, that despite the claim that not many were aware of the finish, enough people, or the right people, must have known. There were two major online betting websites that had Lesnar an unbelievable underdog, nearly 50-to-1 by some odds, that switched to him being an actual betting favorite when the match hit the ring, indicating that a ton of "smart money" came in once the finish was determined and told to whomever was in the loop to know these kind of things.
(Credit: Wrestling Observer Newsletter)