Hmmm Joel does that "mad bite" only when i'm taking something really good out of his mouth, he just did it today on a walk when I took a chicken bone away that he found.
But what I do is definetly dont pull my hand away so he thinks it doesnt bother me and I also push my hand farther in his mouth, so I do the opposite of what he thinks im gonna do. He has been doing it less then before.
Hope that helped