20 Things You Somehow Missed In Die Hard
3. John McClane The Bartender
When McClane makes a passing reference to being able to spot a fake ID, Al Powell knows precisely what he means and feels that he is working with a professional; Dwyane T. Robinson, however, stands in the way of things (as becomes the norm throughout the film) and complains that McClane may just be a bartender rather than a cop for all they know.
This is a reference to one of Bruce Willis's earliest careers before he became an actor. He had left school in 1977 and moved to Hell's Kitchen in New York City where, in the early 1980s, he supported himself by working as a bartender at the Manhattan art bar, Kamikaze.
Again, it all contributes to McClane being portrayed as the everyday man confronted by a seemingly impossible situation in this film.