 The producers worked hard to keep the ending of the episode a secret . While it was in production , David Silverman was the only animator who knew who the culprit was . Wes Archer , director of the episode , was initially unaware of the solution and directed the episode up until the conclusion . When it was time to animate the ending of the show , Silverman and Archer waited until the end of the summer of 1995 to work on it . They realized they needed help with the layouts and started giving various animators small parts to work on without telling them who the culprit was . The table read for the episode also ended before the third act . The writers had wanted the clues that were animated to be just right , so there were many animation retakes . 
