Something in it's humanoid isn't letting me make all the children of the NPC CanCollide false...
There's no way to do this, as confirmed by one of the Roblox employees (admin NobleDragon) in a twitch feed today who said their programming prevents this from happening. (See the twitch broadcast regarding their 1000 subscriber celebration and give away party). Somehow he DID walk thru a person and was shocked, but it was decided that it was a statue of the game owner, I believe - and not a real player.