Batty calls Deckard by name during the chase at the end. How did he know Deckards name?
This is either a technical error in the film, or an indication that Batty knew Deckard, and Deckard doesn’t remember Batty. One theory is that Deckard (and possibly Rachael) were replicants, and part of the rebellion. They were caught alive entering the Tyrell building, and as an experiment they were retrained as an ex-Blade Runner, and a replicant who think’s she’s a human. The experiment was to see if a replicant could turn on other replicants that he/she used to know. This explanation is a bit weak and far fetched, as it relies on the Tyrell corporation retraining Deckard but not changing his name. (Imagine if Roy had called him “Mr Smith”!) This makes the Deckard/Zhora confrontation more interesting: she would have recognized him, and would be wondering if he was having a joke or not. When she realized that he was for real, she clobbered him. This could also give Bryant an excuse for getting the number of escaped replicants wrong. Different versions of the script have Deckard as a
