http://flame.tiefighter.org/WoW/1115793473.wmv
Some info I got from a friend who is a level 60 on WoW:
Right around that corner they were near is like the biggest boss in the game. The room they went into was optional, and only for if you needed this shoulder equipment (the pauldrons they mentioned.) Leeroy there was the only one who "needed" anything from that room, as they said in the dialogue. However, he didn't need it at all. It's equipment for priests (he's a paladin), but he says it gives him mana, which helps him heal better. That's why the guy was like, "Christ..." So he ended up ruining everything for them, for an item that nobody needed, and he was AFK the whole time for the mission briefing. That explains the dialogue a bit. As for "32.333" chance of survival, that guy is just a geek.