I was at that fight, and Shogun clearly should of won the decision. While both fighters were pretty even, Shogun was the stronger fighter, and took the initiative and got some great punches. Red welts on Machida where his ribs are, and after each round, his corner had to put ice on his leg muscles because they were heating up and probably tightening. Shogun needed nothing, and was determined to win.
When they announced Machida, there were a chorus of boos around the arena, although there were also a good amount of applause, as Machida fans were aplenty in that arena.