barbadosan, thanks for posting the interview with Tips after the match. He did mention that he came with a game plan, and that he talked with Djoker about strategy.
Well, in my opinion, I think Federer at one point became too predictable with his return game. He was trying to slice everytime, and Tips was very well prepared for it. But, if you notice that when Fed mixed up his return game a bit, with some flat hitting and also slices, he was more successful.