Murray was incredibly lucky during that match. He hit so many shots that just happen to land right on the baseline. The law of probability would have dictated that half of those shots should have landed long but he kept hitting the baseline. That's pretty lucky, if you ask me.
Yes, Murray played extremely well and Federer served terribly but Murray's luck certainly didn't hurt.
Murray wasn't lucky, he was simply played well. If it were Fed hitting those shots you wouldn't say it was luck.