Berdych is a tit - from what I heard, even Andy was sceptical that the hat falling off distracted him.
I didn't actually see the incident due to stream freezing (but many thanks to those who explained what happened), but this article seems unimpressed with Berdych...
Minutes later, with Murray facing a break point in the fourth game, he raced forward to get to a short shot, and a combination of his momentum and the wind pulled his white baseball cap off his head as he made contact with the ball. At the other end, Berdych failed to get to Murray's response, and Maria initially awarded the point to Murray, making the score deuce.
But Berdych argued that he was distracted by the flying hat and engaged the official in a bit of an argument. Murray approached and injected himself into the conversation, asking Berdych whether he was certain the hat affected the outcome of the point.
"I'm just asking if you're 100 percent sure," Murray repeated.
It was a true act of sportsmanship
, leading to Maria's ruling that the point should be replayed. Murray tried to chip a lob that landed long, and Berdych got the point -- and the break.
More at http://espn.go.com/tennis/usopen12/story/_/id/8353280/2012-us-open-andy-murray-tops-tomas-berdych-windy-open-final