A foot fault is a foot fault, plain and simple. That line judge has a job to do, and she did it. If she foot faulted, it has to be called, thats the rules of the game. You cant say it was over-officiating or it wasnt the right time to call it. So when its the last point and a ball is close but out, should the line judge not step in and call it out? No.
For the record, the match did not end on a default because she yelled at the line judge, it was because she got a point penalty for yelling at her, and it happened to be on match point.
Serena showed her true character tonight, and thats what she gets. Sucks for Kim, she didnt get to enjoy the win like she should have.