 Several of the cast members had experience in martial arts prior to the filming of the episode . Rainn Wilson used to study karate and is a certified yellow belt . Krall is a black belt in Taekwondo and was nationally ranked . One of the girls who played one of Dwight 's classmates was actually a black belt , but was forced to wear a white belt ; ultimately , she was unhappy about having to hide her ability . Eventually , she vented her frustration by " practically knock [ ing ] Rainn over when she kicked the pad he was holding " , which was included in the episode . During the filming of the episode , the protective piece of headgear that Wilson wore actually cut him . 
