This makes me smile, although I understand your concerns. Let's just say a strong desire for accuracy runs strong in our household...
I'm not sure I would start with a book. I think I might sit down (or walk with) him and ask some open ended questions. Such as "You went out of your way to find the email for your sister's teacher and contacted her. What were you thinking you might accomplish by doing that?" (Listen) Depending on the answer, more questions.
For example, "I can't stand that she is telling them the wrong info." "Okay, I know you like things being accurate, but how might a teacher feel if someone she/he didn't know sent them a message telling them they had told their class something wrong?" Then let that go into a teachable moment, explain that we need to consider how someone receives communication, not just our need/desire to send it. Have him think of other ways to address a situation like that, etc. etc.
I personally wouldn't jump to this being respect vs. disrespect. Those imply intent. It's possible that this is more about how one's actions are perceived and taking the recipient's point of view (and emotions, status as a teacher, etc.) into account before acting.
It might also be a time to explain "chain of command" or "not going over someone's head" (in this case, his sister, who is the teacher's student and should have been the one to talk to about it first).
