What relationship does Charlie have with Bill? Is this a healthy student/teacher relationship?

BIll is Charlie's teacher and mentor. Yes, he crosses the line. You don't let students come to your house, you don't allow them to smoke in your office, and you don't become their friend. Mentor—yes. Friend—no. Regardless, maybe Bill knew he had to go the extra mile for a student in trouble. I won't condemn him for being a positive role model or helping a troubled student, but I won't excuse those little mistakes either.