Do not believe that was Sean Tucker although cannot for some reason get the clip to play again.
Correct, it was Skip Stewart, and the manoeuvre is his signature act, the low and slow "knife edge" performed in one of his two custom Pitts biplanes.
He has also done stuff like flying under a jumping motorcycle. Crazy? Probably. A crowd pleaser? Most likely.
All things considered, he's still young, started young, and seems to know what he's doing. There would also seem to be certain preparations and precautions in place to ensure the safety of the flight and onlookers.
EDIT -- This link to the clip in question appears to be working:
https://www.facebook.com/teamladsban...7988550783735/