Free Scotch

The bartender asks the guy sitting at the bar:

- What'll you have?

The guy answers:

- A scotch, please.

The bartender hands him the drink, and says:

- That'll be five dollars - to which the guy replies.

- What are you talking about? I don't owe you anything for this.

A lawyer, sitting nearby and overhearing the conversation, then says to the bartender:

- You know, he's got you there. In the original offer, which constitutes a binding contract upon acceptance, there was no stipulation of remuneration.

The bartender was not impressed, but says to the guy:

- Okay, you beat me for a drink. But don't ever let me catch you in here again.

The next day, same guy walks into the bar.
Bartender says:

- What the heck are you doing in here? I can't believe you've got the audacity to come back!

The guy says:

- What are you talking about? I've never been in this place in my life! - The bartender replies.

- I'm very sorry, but this is uncanny. You must have a double.

To which the guy replies:

- Thank you. Make it a scotch.