Actually, Alton says that nothing he says is ever scripted. He claims that they have gone back and rerecorded the voiceover in some places because of audio issues, but when they do he doesn't change what he originally said, even if it was wrong.
He did however claim that he occasionally intentionally makes mistakes or act like he doesn't know what an ingredient, etc. is because he doesn't want people to think he's a know it all... HA. Actually, I've caught him doing that on a couple of episodes. He asks what something is because he's "never seen it before", and when the chef gives it's name Alton all the sudden knows everything else there is to know about it... except apparently what it looked like.
As far as knives... I'm pretty sure I've seen a Carter on there before, from one of the challengers. And maybe a Hiro AS as well... there aren't TOO many makers out there working with stainless clad carbon knives, and that edge patina is pretty unmistakable. I think the Carter was a wabocho. Other than that, a lot of Nenox, a lot of Shun, several Suisin, some Misono. I've caught quite a few of those on the show before.