Honestly, that seems very fair. Because of the way retina screens upsize images you actually get a clearer view of how it looks at 16 pixels in a standard screen by being served the 32px when using a retina one.
Can you explain what you mean with that? Surely an upscaled 16px image is more comparable to a crisp 16px image than a crisp 32px image is to a crisp 16px image, unless you want to argue that the 16px images are hand-crafted for crispness over form.