A minor character is named Robert here despite being named Jeff in a Season 1 episode.
Boom mic can be seen during the movie theater scene.
Neither Robert, nor anybody else in the school pulls the Fire Alarm despite the Chemistry Lab being on fire.
Kelly tells her father that there are 7 people in the family other than her and she doesn't want to be selfish. In season one she mentions being one of 7 children. With 6 siblings plus her parents, there are 8 other people in her family, not 7.