To call in a "travesty" would be a gross exaggeration, Man Utd would have been unfortunate, but its hardly anything more, unless you take it too seriously off course.
My prediction is that Arsenal will take the game 1-0 and then probably go out in extra time, that said, if Arsenal concede then the game will be as good as over.
And yes, RE: the above point, the fluke I was referring to was the fact that Carrick's cross was going away from all the Man Utd players in the box till Silvestre deflected into the path of O'Shea, the finish was obviously not a fluke.