I don't know if they get ear infections. It could have something to do with the legs not getting good blood flow, but I would think that by now, things would have returned to normal if that was the case. I had a rooster that caught his toe on a eye hook, and was hanging upside down by one toe. I do't know how long he was hanging, but it only took a day for him to recover.
I think, for now, it might not hurt to give him a drop or 2 of liquid baby vitamins each day. Having a little extra vitamin doesn't hurt. Have you tried massaging his legs, to feel for anything out of place? Do you think, by looking at him that his head is getting fuzzy, or are his legs giving out?