I'm hoping it's his dry sense of humor. He's also pointing out how the replicants have a problem with red-eye: "it's unfortunate that the producers couldn't find a way to work around such a simple photographic bugbear." In fact the filmmakers took great pains to add this golden glow to the replicants. It's no accident at all. In the Final Cut DVD, they talk about how they did it. I'm sure that Dave Addey watched this bonus feature, as analytical as he is. He mentions Harrison Ford's eyes catch this glow at one point, saying, "How strange! I'm sure it won't turn out to be significant." This must be more dry humor, because there's also the fan theory that Deckard is a replicant after all.
