Holy crap, people have actually made it far enough into that video to see what inconsistency in the Diablo lore he was actually talking about? It's just so unbelievably awkward that I can't take more than 10 seconds of it. I'm no social dynamo, but there's not being sociable and then there's that.
And people are hailing him as a hero for this? Even he had been capable of a non-awkward delivery, who honestly gives a crap about some incredibly obscure inconsistency in the lore that derives from the books of all places (at least I think it does from what I've gathered... like I said, couldn't sit through the entire video). Yeah, cool, like all franchises that expand far beyond the boundaries of what the original designers and writers ever intended, inconsistencies have developed for various reasons. There's nothing surprising about the devs at that panel having no clue what he was talking about -- I highly doubt any of them have read the Diablo books or have spent a whole lot of time delving into every obscure factoid of the Diablo lore. Pretty sure they're all a little busy, y'know, making the game. I actually don't even like Jay Wilson very much, but this is a pretty lame thing to go "gotcha!" on.
Was Leonard Boyarsky at that panel? He's the only developer I'd think might be able to respond to that. But still, I couldn't even fault ol' Leo for not having a response. That SNL skit with William Shatner at the Star Trek convention is really quite apt.