Continuity mistake: When Marley is walking to meet Rourke at the cafe, look behind her as she turns the corner and comes to a stop. You will see a woman inside the cafe behind her take a sip from her coffee. The scene then cuts to a close-up of Marley and we see the woman inside the cafe take that same sip of coffee again. There was not enough time for her to drop her hand and bring it back up again to take another sip.
Trivia: When Dustin Hoffman and Gene Hackman have their showdown in the lavatory towards the end, Hackman greets him and says that this is a "long overdue pleasure." This is a reference to the fact that this scene is the first scene ever between Hoffman and Hackman, two former classmates at film school, in their substantial screen careers. Despite being in the industry for decades, and being long-time friends, they had never made a movie together.
Trivia: Everyone walks around the French Quarter drinking Starbucks coffee. There isn't a Starbucks very close to the Quarter. The closest one is also hard to find. When I'm there I usually drink Cafe du Monde coffee while walking around the Quarter.