John Isner had his second match point over Jordan Thompson, at 6-5 in the third-set tiebreak of their Rogers Cup match, when a Thompson forehand landed somewhere near the left sideline, well out of Isner’s reach. There was no call from the linespeople or ump; Isner used his last remaining challenge. Hawkeye, a system which uses video from six cameras to produce a representation of the ball’s path, did its thing. The resulting call was a paradox.
In the representation, the ball landed in but was ruled out, which is not something I can recall ever seeing.
The umpire got on the radio and chatted with an unintelligible voice. “Tell me how is the ball, just to know,” he asked. After a confusing silence, play continued as if the ball had landed in. Isner won anyway.
[Tennis TV]