Maybe, maybe not - and that answers both of your questions! Regarding being right vs. fostering harmony, it totally depends upon the situation. The saying is true: pick your battles. Is "rightness" very important, and not just to you, but to the person you're talking with (even if they don't recognize it ATM) and/or others? Do battle. If not, harmony is a better approach. Example: You're in an auto race with a guy who decides to take a shortcut over a particular bridge you know is out, so you get on your headset and warn him about it. He laughs and accuses you of trying to deter him from taking the short cut, and keeps heading towards the bridge. Good time to do some battle.
Was that a ridiculously long response, or did you find it meaningful?