I've kept lots of 'African Cichlids' and never had any of them pick out an eye of another fish. African cichlids describe a hugely broad group varied in both size and temperament.
I've never heard of any fish picking the eye out of another fish if there wasn't something already wrong with the fish to start with. The GS probably was/is sick or stressed out, and it's not unusual for other fish to pick on sick fish, and the eyes are the weakest part and normally the first to go.
This, with the fact that you say the fish does not want to eat sounds like you do have a sick fish that probably does not need to be in a community setting if you want to have a good recovery time. A stressed and sick fish in a community tank might just get picked on more, and just stressed out more leading to a quicker death.
I've got a juvenile male Gold Saum and if he doesn't act like he hasn't had anything to eat in a month even if I just fed him 10 minutes ago I would know something was wrong. Keep an eye on him in the community tank, but I think the immediate concern right now is the fact that he won't eat. No food will lead to a harder time for current wounds to heal, opening to door to infection and more stress.