Writer Michael Peterson's daughter has Neurofibromatosis Type 2, and he wrote the disease into the storyline to raise awareness about the illness and its incurable nature. He did an interview regarding this episode and NF2.
Often seen as an error, Angela's helmet during her tryout for the roller derby team changes throughout the scene. When Angela wears the cover on the helmet with the star, she is skating as the jammer, the point scorer who is attempting to lap the opposing team's players. When skating without the star cover on her helmet, she would be part of the team members that try to assist their jammer in lapping the opposition. It would make sense that during a tryout a potential member would be asked to skate in different positions on the team to see if she would be a good fit, hence the addition and removal of the helmet cover at different points during the tryouts.