That actually was something of a homage to a classic film noir film, The Big Sleep, starring Humphrey Bogart and Lauren Bacall, where Bogart plays private investigator Phillip Marlowe. In the film, Marlowe goes into a book store that's a front for a black-mail operation, and he adopts this rather snooty persona, puts the bill of his fedora upwards and wears glasses, and adjusts his voice. You see this a lot in detective fiction where the detective does this in order to break up his identity just enough so that if the opposition sees him, they won't immediately identify him (because the detective often doesn't know who's among the opposition).Much of the failings can be attributed to Ridley Scott and the studio-interference really though. For example, the one scene when Deckard gets into Zora's changing room pretending to be that wierdly creepy inspector, which is really out-of-character for Deckard and doesn't make any sense in terms of being a believable way to get to her?
In Blade Runner, Deckard goes in there knowing that potentially this is Zhora, one of his targets, and wants to lull her into a false sense of security so that he can kill her without much fuss. If he went in guns blazing, one, she might get away (which she does) and two, it might cause a lot of problems at the club because cops know that when there's gunplay, people tend to panic. Zhora is an assassin, and she's potentially much stronger and much faster than Deckard is, so he has only one chance in that dressing room. Also, I'm sure he's completely wasted from all the booze he drinks.
My big issue with Blade Runner is Ridley Scott not leaving well enough alone. I could understand him removing Deckard's narration, but by declaring outright that he's a replicant wrecks the ambiguity. But, more importantly, if he is at all a replicant, that issue isn't really something of a consideration throughout the film. Meaning, okay, if they want to make it ambiguous, Scott could've provided more clues. The thing that kills the idea is the notion that the cops would use Deckard if he were a replicant, because by giving him the Voight-Kampff machine, they risk him using it on himself, and if he does, what then? He's in a position to kill Gaff if he has to, skip town, or worse.....go to the press. But, I'm sure Scott would say you can't trust what he's putting on screen.
