If someone's heart is in the right place, he or she has good intentions and wants to be kind or helpful. He's stubborn, so he doesn't change his mind easily. Once he has decided something , or metaphorically "started down a certain road," you can't convince him to change his mind, or "turn back.""I'd rather not get involved with any differences.." means I don't want to take sides in the arguments you have with him; I know you and he disagree, but I don't want to be involved.