I imagine he would disagree with you. Many of us are able to be reasonably fluent when giving prepared presentations. It's the unprepared conversations (social interaction) where the disfluency really comes out. I stutter a little bit worse than this guy does. Probably not as bad as you do given your reaction. But it has still been a plague in most aspects of my life. Good on this dude for taking the risks he has to get where he is.