not exactly, the human psychology is something hard to comprehend. Federer needed to return Haas' shots with a lot of power in order to stay in the point.
At the beginning of the match, Haas was merely keeping the ball in play, allowing Federer to dictate play. But by the 3rd set it was quite the opposite, and Federer couldn't dictate, and he found it hard to compensate; hence the so called "unforced errors".
I completly agree with rnitya_25, for once
She recognized that Haas improved his play in the 3rd and 4th set. Which is true.