Deconvolution can only do so much. In particular, it tends to introduce "ringing" artifacts, which are particularly visible in this animation around the limb (edge) of Earth and in the form of a concentric ring on the Moon, particularly when the Moon is crossing Earth's disk. A wonderful thing about this blur problem is that scientists made lemonade from lemons by using the HRI to observe exoplanet transits across distant stars. The camera couldn't resolve the star no matter how sharp its vision was anyway, and by having the star's light spread out across many pixels with the blurred optics, they were actually able to get much more sensitive measurements of the amount that the star's light dimmed with each planetary transit.

So there you go. It's funny that for all the images that we have of moons transiting other planets (some of which I'm including below), this is the only one that I know of where both Earth and Moon appear as full globes, with the Moon transiting Earth.