I didn't really understand that either. He keeps seeing the "woman in black" throughout and then just passes her at the end before walking into the apartment room -- I didn't even realize it was DeNiro, I'll have to go back and look at that. I just thought it was some clean shaven guy (the real Devil?) and was symbolic for that reason.The weirdest shot in that movie is when Roarke returns to his hotel near the end, and passes a nun (or a woman in a long dress -- its been a while since I saw the film) and "she" looks up and is revealed to be none other than Robert DeNiro! Not quite as strange as Sean Connery in a wedding dress in Zardoz, but up there!
There was also a shot of Dann Florek (who plays the lawyer at the beginning of the movie who accompanied DeNiro) getting offed in the trailer it looked like, which wasn't in the movie I believe.