Since you mentioned it, I have to say that I did practice and learn from eyeballing and tracing myself (I was like...14 at the time!). And then you do it again, try to put it in a new pose with maybe the same head, which looks horrible...but you learn to get that stuff in your head. It's excellent practice and I don't feel badly about those who do it for that purpose, even with my own art.
However, it's like I told him: It's fine to do this for practice. It's not fine to claim practice work as your own when it's just a trace or eyeballing.