When Agent Handratty climbs the stairs at the hotel where Frank is staying, he has his gun drawn. As he gets to the top of the stairs, he surprises a hotel maid. "It's okay, ma'am, FBI" he says and holds open his wallet, with the credentials facing himself, and the back leather cover facing the maid.
Ugh! This is NOT a slip up....It was done on purpose to show how fumbly the FBI agent is. It's supposed to be funny, and it was supposed to be in the movie...it's not a slip up.