When Garotte overhears a mother in the street calling her son a bad boy and turns to follow her to kill her, the scene then cuts to Jake and the replicant, where an entire day goes by showing the replicant being "trained", but when it cuts back to Garotte as he is moving in to kill the woman, it is clearly the same day as he when first "met" her as she is wearing the same clothes.
Replicants came from the Screen Writer of Blade Runner, David Webb Peoples' daughter, Risa, who was studying microbiology and biochemistry. She introduced her father to the theory of replication - the process whereby cells are duplicated for cloning purposes.
Why was Garrott so passive and couldn't quickly put away Jake and the Replicant, who were supposedely inferior?
There are at least several answers to this rather good question that seem a bit vague. Garrott had a few encounters with both Jake and the Replicant. Anyway, here it goes.1) Garrott was a killer who enjoyed using stealth to slowly torment its targets without getting caught-using brute force would expose himself to the public eye and could risk harming bystanders that he didn't have much intent to kill.2) Garrott's goal was to prey on its primary targets and not waste time with other inferior interferences-meaning that every moment he spent with the Replicant and/or Jake, he would lose track of his primary targets.3) As an incomplete prototype, the Replicant did not possess Garrott's anatomy/weaknesses or was not built to fight him.4) Garrott wanted to make the most of his kills by keeping Jake and the Replicant as leftovers-meaning that he would only hesitate to kill Jake if he kept on testing his hand.5) Garrott and the Replicant were possibly genetically linked-even after all the mind games and encounters, neither decided to kill each other until Jake decided to come into the bigger picture.6) The Replicant had learned to become more complete over time. As an incomplete prototype, he did not possess full mental and physical abilities to completely combat Garrott. This was shown in the final autopsy lab where Garrott decides to brutally slaughter Jake for the Replicant to fully understand that Garrott was an evil killer and to finally go hand-to-hand with him-this meant that both proved to be an even match at the climax of the scenarios until Jake finally managed to bring things to an end.7) In general, the Replicant was not easy to kill-the fact that Garrott put a gun to his head didn't mean he, himself, could take him hand-to-hand that easily-the anology would be one fighting a twin sibling of one' self-one may be a bit stronger but the other can even things up and fight back to a reasonable extent.