I never gave too much thought for this. But now that I'm thinking, I believe that anyone can hold the pencil how they feel comfortable and this is the right way to hold the pencil. Me, for example, as a right hander, I'll hold the pencil a little bit inclined to the right, while my wife, being a left hander, she'll keep the pencil bent over to the left. So I believe it's truly a matter of choice and comfort!
RE: Pencil Grip: Right or Wrong