"Experts" are a dime a dozen.
I used to work with this insurance guy, Tony, who taught me how the pros forge signatures. The secret is to turn the signature which you are duplicating upside down. That way when you forge the signature you are only duplicating what looks like a scribble instead of a group of letters. This negates any predisposition you have in the way that you normally write those letters. With a little practice, this method works amazingly well.
Tony was clearly an "expert". Maybe CBS asked Tony.
In the old days, that was also how bank tellers were taught to compare signatures on checks against signature cards - upside down.