to be clear, they were surprised that a chip reader worked WITHOUT a pin. and that I couldn't contactless. Everyone was saying "tap here" when I walked up to pay. "no tap". Pretty much every purchase.

They didn't know all the bells and whistles on their machine. It'd be about as surprising as if I whipped out a personal check and they found their machine had a reader for that.

Which would imply that the waiter is in fact quite savvy since they understand the intricacies of credit card authorisations for different countries.

Not particularly, anyone here who deals with sales for any amount of Americans will quickly see that they're the odd one out with contactless.

It's not that there's heaps of different scenarios, it's that there's America and the rest of the world.