Federer may have not shown how upset he was on court (other than in his lackluster play and dispirited demeanor in the 5th) after giving away the 4th set from 40-0 after having many chances to break during the set, but in his press conference, he said he was very angry with himself and sad about it and you could see and hear it. Basically he said it should have never happened and doesn't know why it did. He said he had been the better player in the entire set till that point, and that he had to at least make it go to the tiebreaker, and if Milos had won it there, fine. But to lose it like he did was not explainable. I think most would agree.
He also said that fall he had was different than he ever had before when he fell prone to the turf in the 5th, and he was concerned about it. He walked it off during the match, but he thought he would have to wait and see what it looks like in the morning and the next few days. He was clearly disappointed because he felt so close to winning it and didn't, but then on reflection he felt he overachieved considering how he felt coming into the tournament where he wasn't sure if he was match fit enough. At the very end of the English part of the press conference one could see and hear he was upset about not winning the match when he said how it turned very fast.
In any case, once Raonic got the gift, he ran with it. He played quite well in the 5th set, given the new lease on life, looked much freer on his serve and once he broke Federer he held serve rather easily.
So congratulations to Milos and his fans, good luck in the final, and commiserations to Roger and his fans.
Respectfully,
masterclass