I'd try him in the hospital tank and hope. Keep him as stress free as possible - maybe give him some shelter with a rock or something.
Unfortunately for us, any fish that can eat a fish, will. I lost a school of neons to an angelfish that way. There were other neons in the tank with the angel, but when I added the new ones, they were small enough to be lunch. sigh...
Good luck- hope he makes it.