The GT-R is blindingly fast. It had a similar experience at Nurbergring. Blind is a good thing 'cause it is monstrous looking.
I am actually surprised the 997 Turbo outran the Z06 at Buttonwillow. It has tons of HP and grip but it's heavy and not usually a great track car. They are often found at the bottom of a track day results page. Novice drivers who bit off more than they can chew I think.
Steve Millen is a great driver. He is a former rally and offroad guy back in my day who later got into open wheel, 24hr Le Mans, and other series and always did very well.