Was the call against Serena justified?

In the US Open women's final between Serena Williams and Samantha Stosur, Serena got a point taken away from her for yelling come on after hitting a lethal forehand. Serena yelled come on immediately after hitting the shot before Stosur's racquet touched the ball. The fellow who commented below is correct about the rule. Yelling come on like that is obnoxious anyway. Serena has gotten a lot of bullshit calls in her career. This one was not really one of them because the umpire can make the call she did. She thought Serena's yell was trying to hurt Stosur. I could be wrong about that. I do not think that Serena was trying to hurt Stosur. Of course Stosur won the match anyway, because Serena was just simply not on her game. Congrats to Stosur. I wrote that she could not close out matches in my previous blog. Well, she must have read it. Yes, that's it. Yeah right, I'm kidding around. The match is over, but was the call against Serena justified. She did not think so, and she had some words for the chair umpire. In my opinion awarding the point to Stosur was not the right move. If I were the umpire I would have had them replay the point.. Since it is up to the umpire to make the call, Serena should not have verbally abused her. I love her charity work in Africa. The fact that she is starting schools for poor children, and puts that above tennis in importance is commendable. But, come on, her come ons are a bit excessive and she keeps exploding at chair umpires. Stosur had no play on that ball from what I saw. A robot would not have had a play on that ball, and no one on the men's side would have had a play on that ball. Serena has gotten so many bad calls in her career, I have lost count. Venus has too. Serena used to get more hurt by that treatment than angry. Now, she gets angry because she has had enough of the bullshit. After viewing the exchange a few more times, the umpire saw it a certain way, and made a call which she had the right to make. I did not sense any type of conspiracy or racism against Serena in this situation. That crazy call in the Capriati match a while back was messed up. That situation was very different than this one. The point should have been replayed, but the bottom line is Stosur pulled off a great upset and won the first grandslam for a female Australian player in over thirty years. It was her day today, not Serena's. I really liked Stosur's subdued reaction after winning. Excellent sportsmanship from her, and a well earned victory.