The author’s premise is bogus from the start, since Deckard had previously quit because of his guilt over the job. Remember the voice-over in the original, where he didn’t react well to praise for killing the first female replicant, saying, “..it didn’t make me feel better about shooting a woman in the back.”
Thus raising one of the fascinating questions in the first movie: Is Deckard the good guy or the bad guy in this movie?