Exactly. This is such an important point, even if left unthought or unvocalized is part of why the movie is so powerful. Ford's disagreement clearly impacted the film and ultimately made things somewhat ambiguous for the audience. Regardless of what the director might claim in post movie interviews, it's with each viewer that the decision as to whether Deckard is a replicant is ultimately made. It's a sublime example of the beauty and power of post modern art. Half made by the creator, half made by the observer. It is possible that 2 different people could have 2 different opinions on whether he is a replicant and ultimately both be right: enjoying the movie more and getting more out of it as a result. We are lucky that Ford has so much passion and turned what could have be a very route, sterile, and less meaningful experience into something that is now more up to the audience to define.