I understand shooting fully by instinct, I do it too now after giving up on target archery, but even a good instinctive eye will not cause a wrong spine weight arrow to fly true, he even cut it down ( this will alter it's weight, his draw length and probably the spine weight also) and it still flew to target!!!??!! Thats hard to believe, I'd love to see the guy in the flesh, he must be an impressive character!
Maybe he makes the arrows instinctively as well. He just makes them so they feel right and then they shoot properly?
Just a thought
Edit:
Just found a another vid by Fredde Norgren demonstrating more of his awesomeness with his bow
http://www.youtube.com/watch?v=03i3cSNuKzU&feature=channel