Mario Yamasaki explains his decision (Zuffa)Erick Silva rode a roller coaster of emotions at UFC 142. After taking out Carlo Prater in 29 seconds, Silva celebrated with the loud, Brazilian crowd. He was brought down to reality when he was informed by referee Mario Yamasaki that the blows Silva used to knock out Prater were deemed illegal. Though a replay showed that the blows hit the sides of Prater's head, not the restricted area on the the back of the head, Silva had been disqualified.
The UFC confirmed that Silva did receive his win bonus and it's unlikely that this loss will stunt his career's trajectory, but it didn't need to be a loss. Yamasaki admitted when talking to UFC commentator Joe Rogan that he had to make the decision in the moment.
"I have to decide right there and then. There's nothing I can do," Yamasaki said.
In that moment, there was nothing Yamasaki could do. Instant replay does not have a place in MMA. Though he watched the replay on a giant screen just moments after the fight ended, the bout was decided.
With the technology already in place for referees to use instant replay, there is no good reason for MMA not to use it. Instant replay is used in other major sports. Though it isn't always perfect, it gives referees confidence on making calls.
Like in other sports, strict parameters of when it should be used would need to be put in place. For example, it does not make sense to use instant replay to decide if a fighter was truly knocked out or not because of the difficulties in restarting a stopped bout. But in the case of a disqualification, instant replay can and should be used.