How big are your nems? The Rfa could have eaten it but personaly I think it's possible but also sort of unlikely. As long as it was healthy. MOST healthy fish easily escape from rfa. Especialy small rfa. If it even tries to eat them. Mine usualy recoil away when fish blunder into them. Dead, Sick, weak or injured I could guarentee it would eat it or at least try too. I suppose if the fish was sleeping, scared or disoriented one may have gotten lucky but I would still keep any eye out for the fish. I hope it shows up.