The guy who walked away was there. You and I were not. As such, he had the ability to read body language/non verbal cues coming from dipshit with a pistol. Whether he did so and called dipshit's bluff or simply lucked out we will never know.
To answer your question, yes, sometimes the best defense against someone drawing down on you is to disengage and escape. Maybe even without drawing or firing back. Exactly what that situation would be, I couldn't tell you in advance. All this shit is incredibly fluid and every situation is a world onto itself.
One thing is for sure. The guy who walked away won the confrontation without a ton of potential legal and financial hassle, which is always a real possibility when you draw your weapon in earnest, let alone fire it against an aggressor.