Hampton Fancher I think once said the question is more interesting than the answer, I'm inclined to agree, although once you notice the nudging in the sequel it's more funny than anything else.
They were stuck in the sequel, needed Harrison Ford (who has aged dramatically) to be in the film for financial reasons, and also needed to pay lip service to the supposed answer. So I think there's one scene that outlines how it could be possible that made no sense but was clearly shoehorned in there.
I think that was more of a nod to the writer's and I assume director's respect for but disagreement with Ridley Scott's thesis.
They don't actually think Deckard is a replicant, but they're more than happy to channel the idea of him being a replicant, but it's through Gaff where it can either come across as subtle misdirection, a hint to a wayward soul (K), or just playing tricks on someone that presumably took over his job - "something in his eyes".
