It means that the source of this behavior (wanting to help her) was his role as a teacher; it was that element of his character.
If I show up at a catherdral wearing tennis shoes, chewing gum, and speaking English loudly as if that made it closer to the native language, you could point to me and say, "Ah, I now see the American in you." ![Stick out tongue [:P]](/emoticons/emotion-4.gif)