In the episode where Doug wanted to buy a chainsaw that he saw on an infomercial and Carrie told him he couldn't buy it, and that he wasn't allowed to make major decisions in their marriage. So they think back to when they first got married and Doug is at work standing by the lockers shaving 1/2 his mustache off, and on one of the lockers behind him it has Danny Heffernan's name on it. Danny didn't work with Doug at that time. Doug got Danny on in a later episode.