I can't tell from it but he does sure sound on pitch.
Auto-tune works in realtime. It's a digital signal processing system with sub-millisecond lag.
I am hoping that the following have never used pitch correction:ToolGeddyThe Police - whoops!Judy GarlandKaren CarpenterABBAStevie (either one)Glen CampbellTina Turner - RIPMister Claypool, who can boss out on bass at the same time as singing perfectly oddBritney ... hah