It would be nice if you got the translation right, you're obviously not French. What he said was "pas mal" which translates to "not bad". So before you paint your picture, you really ought to get your facts right.
But is that any better, in the circumstances? L'Equipe quoted Federer as saying "I played well in doubles, Stan not bad, but he often struggled on his service games." That still seems pretty ungracious to me.
And explain "Stan didn’t have his best match in singles. It’s a shame, because of that defeat we weren’t able to put the U.S. under pressure" when Stan had taken a higher ranked plyer to 9-7 in the 5th set, while Fed had lost 6-2 in the 4th to a lower ranked player.
Also the Swiss journalist Svenja Mastroberardino, who was also on site, reported that Federer said in Swiss German, "Stan didn't play well and I had two close matches..."
"He criticized Wawrinka more than once [for his play in singles]," said Mastroberardino.http://www.tennis.com/articles/templates/news.aspx?articleid=16408&zoneid=25