Wikia

Red Shirt Guy (also "Red Shirt Kid") refers to a player at BlizzCon 2010 who, during the Lore & Quests Q&A session, correctly pointed out an issue in the story of the game. The questioner is incredibly nervous and speaks stiltedly; however after correcting and even educating the developers on the issue, he has become a fan favorite.

Red Shirt Guy: "Hello, I have just finished reading The Shattering yesterday, and I noticed something, it said that Falstad Wildhammer was going to be on the Council of Three Hammers, but in the beta it's Kurdran Wildhammer and Falstad isn't in the game at all. What happened to him?"
Chris Metzen: "Isn't Falstad dead? From, ah, Day Of The Dragon? No?"
Red Shirt Guy: "No, he survived, and in fact was the leader of Aerie Peak from vanilla WoW and through Wrath Of the Lich King."
Alex Afrasiabi: "Of course..."
Chris Metzen: "Yeah, Alex, what's up with that!?"
Alex Afrasiabi: "Thanks for pointing that out, we're gonna get that fixed."
Red Shirt Guy: "Thank you."

Due to his popularity, many videos have been made pastiching Red Shirt Guy including auto-tunes and rapping.

After swapping Kurdran out for Falstad, Blizzard also included a Wildhammer Fact Checker NPC standing next to Falstad in the Ironforge High Seat in honor of Red Shirt Guy.^[1]

Red Shirt Guy also posted a video "response" to the public and clarified that he spoke strangely due to nerves and hearing his own voice on the speakers; he also mentioned he has [Asperger Syndrome]. He would not give out his character name to avoid excessive messaging (well-meaning or otherwise), but instead mentioned his guild and server.