Other mistake: Noonan is supposed to be a New York cop. When he hands Frankie his badge it says Boston police.
Continuity mistake: When Terry enters Kathleen's apartment for the last time (the scene with Robin Wright in a towel, late in the movie) he barges through the door, and both go to another room, not shutting the door. Later in the scene when Kathleen goes to leave, the door is closed.