Instant replay would have helped longtime referee “Big” John McCarthy make the correct call in a 2011 fight between Mackens Semerzier and Robbie Peralta. After Peralta caught Semerizer with a flurry of punches at UFC on FOX 1, he was awarded a TKO victory. When arena monitors replayed the ending sequence, however, McCarthy realized an accidental headbutt had set the finish in motion.
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