I don't think he was trying to show off that he could solve it in 5.71 seconds - I think he was testing his turn times. He did it back slowly afterwards - a LOT of speedcubers know a particular scramble and know the solution to it, so when they do solve, they can basically see what the theorhetical speed limit would be pretending you could see faster than you're turning. *which is why he had the calculator there - to see how fast/tps he was doing*
I was more impressed that he did get +5 turns per second, but on a scramble that takes 35 moves to solve *sigh*
I thought it was neat regardless
