Ironically, the only time I was ever threatened by restaurant staff was in a snack bar in Wengen, Switzerland and over a plate of spaghetti, to boot.
We were a bunch of entitled adolescents, having a larf of some sort at the expense of the Swiss miss waitress. I was invited downstairs where her S.O. or big brother was doing the cooking.
For the rest of our stay, _I_ made sure no one got out of line.
I was 19. Had travelled by myself for 8 years by that point and was glad to receive such a reminder to be respectful of others.
https://www.youtube.com/watch?v=9DZNDEqcSi0