You'll need to have a little chat with your dad.

Too forced man...

Sounds like a great manager.

You're going to have to tell your dad he can no longer have Juan more drink at that restaurant anymore.

The good news is that Hog n Jog (aka, Dine n Dash, Eat n Cheat, Chew n Screw) is not an inherited trait.

should have told him where to go

I personally would of told the manager that they allowed it to happen and it has nothing to do with me

Not your tab, not your problem. How did he even realize you were related? Same last name?

Maybe small town and knew their family a bit or saw them eating together there some time

Dad sounds like he's developing an alcohol addiction, honestly.