He simply remarked about what he saw on film. Go listen. He said that Elam was hesitant at times in his technique, that he seemed to lack confidence (understandable given his situation), that he turned his body too long before squaring against the receiver, etc. He gave some very specific feedback. It sounds to me like it is mainly technique and confidence that he needs to work on.
Marino didn't say he had all the answers, just that the problems he saw look fixable. Maybe Elam will never be able to fix them. Maybe he will never be able to play proper technique without hesitation. Maybe he'll never get his confidence back. That's not really the point. The point is the stuff he needs to work on require working on technique and gaining confidence, which are things that any player could feasibly work on to improve. Elam might not be able to because some kind of mental block. Who knows?