A gentle answer deflects anger, but harsh words make tempers flare.
For the most part, people respond to us the same way we respond to them.
Just like when someone gets angry at someone else who cuts them off in traffic. If the other person offers a friendly smile and a wave, that usually resets the tone. The angry driver just went from thinking, “what a stupid jerk” to seeing another person like himself who made a simple mistake, and they both go on with their day.