Because rather than hiring a professional interpreter, the court let one of the witnesses’ uncle do the interpretations.

The problem occurred because rather than following Ferrier’s instructions of interpreting word for word what the witness said, the interpreter went beyond relaying and started to explain what his nephew was saying.

Usually courts will not allow anything but professionals to interpret for this exact reason. Most court interpreters are trained exactly for this purpose so that there is no need to explain anything that the witness is saying, thus, preventing complications like this one.

Source: http://republicanherald.com/news/problems-with-interpreter-lead-to-continuance-in-auburn-attempted-homicide-case-1.1315986

Another sport that constantly uses interpreters is Major League Baseball. Currently, the majority of the league is Latino based. Often, to avoid misinterpretation, players will hire interpreters whenever they have press conferences to announce anything important, such as a player signing or a player retiring. Another strong presence in the MLB is from Japan.  These players always have interpreters when they first come to the league, for they are still assimilating to the American culture while trying to adjust to playing at the highest professional level of baseball.

A third sport that relies on interpreters heavily is basketball. Next to soccer, the NBA is the most global sport. Many of players have been drafted overseas to come to America so that they can have a chance at playing against the best talent in the world. Also, some players leave America to try to find a job playing basketball in other countries. For both situations, interpreters are needed to break down the language gap for these athletes so they can focus on their job as professional basketball players.