Agreed. A lot of the points seem to be stressed from the point of explaining how important what he does is.
Bring in the UX designer before you’ve attempted any UI work. I can’t tell you how many times my clients have said “I wish I’d brought you in earlier!” The UI changes are often enough to necessitate technical re-architecture. Starting with a good designer from day one will save you a lot of headaches later on...
If they nailed it on their own, they're not going to bring someone in, but still.