This is more a conundrum than a joke, but…

A man walks into a bar and asks for a glass of water.

The bartender takes down a shotgun and fires a blast, just missing the man.

The man says, “Thanks,” and leaves a $5 tip.

Why the thanks, and why the tip?

 

 

 

(From an NCIS episode)

 

The man had the hiccups.