The linesman made a big mistake last night at the US Open when she called "foot fault" on Serena Williams' serve. Looking at the slow motion replay it is clear that Serena did not commit foot fault. And Serena Williams really lost it and yelled profanities at the lady linesman. The linesman said Serena told her she would 'kill her' and Serena Williams said that she never said that. "Replay the tape" so we can hear the truth.