One night at the bar

A man minding his own business is sitting in a bar.  
Enjoying some downtime after a hard days work.  
Sometime later, a drunken, loud, brash man comes stumbling in.  
He's causing a raucous all around him.  
He sits his ass down right near the quiet man.  
This drunk stunk of sweat and booze.  
The drunk fuck turned to the quiet man and said, "What's your issue? Why do you look like that? Why do you look troubled?"  
The quiet man said, "No issue, just minding my own business".  
The drunk didn't like that answer and continued egging the man on.  
The drunk then began to point his finger and demanding the quiet man to get up and leave.  
The drunk didn't like that he was calm and solemn.  
Finally the quiet man turned on the bar stool and faced him.  
He told the drunk that he could annihilate him with one hand.  
The drunk laughed and spat in his face.  
The two went outside.  
The drunk threw a punch completely missing the quiet man, falling face first onto the ground.
When he finally got back on his feet he was embarrassed and enraged.  
The quiet man pulled out a handgun and shot the drunk directly in the head at point-blank range. One Handed.