Haha, good point.
But he may have originally carried her scent, and it just.. changed.. after he experienced life for a few hours. Or minutes.
Yeah, I'm still leaning more toward the latter too. Even children when first born carry a slightly different scent then their mother does. It's just the way living animals are made up. And in Foster's world, IFs are living "animals" of sorts (humans, too), so I'd think that rule of nature would apply to them too.