I think you're spot on observing that it's one game. What is exciting is that each of the freshmen that float around the rotation have now had that one really good game (at least). The consistency isn't there at all but now with Copeland they've all shown they can do it, which is exciting.
I'm not sure I'd characterize Copeland's play so far as out of control or making bad decisions. I'd say it's more that his game has been very imbalanced - he's trying so hard to do the right thing for his teammates on the offensive end of the floor that he's passing up easier opportunities, both for himself and less risky plays for the other guys on the floor.
The dude does appear to have a supernatural feel for passing, and it's been a looooooong time since we've seen that (Z? The General?). But his teammates haven't figured that out, and Copeland hasn't discerned yet when a play that feels natural to him isn't natural for the other guys.
I for one am super excited to see more from him. As much as he could have played better, he's also shown exactly what I hoped for - he's an energy guy and emotional leader with swagger. When the performance lines up with the talent it's going to be really fun, and give us a major competitive advantage.