of course they can and I'm not to claim otherwise. I just feel that if Fed is firing at the top of his game, he can and will find answers to everything Andy throws at him.
However, in truth, I don't expect Federer to be at his very best in the final, should he get there - he hasn't been for the last 4 at least.
The point I'm making is that one of Andy's strengths is his ability to drag the level of his opponent down. If it was a straight game of attacking tennis, played instinctively, I'd agree that Murray has no say if Federer plays his best.
There are too many variables to consider when you try to mentally match up the best of two players. For that reason, I don't like saying that a match is out of a player's hands under certain circumstances.