I would be surprised if he had refused it. Your accent would probably have hinted that he might expect one
To quote Matthew: "I don't have an accent."
In cafes and restaurants the waiters get very good award wages per hour although some of them may not work long hours per week. We want to discourage tipping there. Some now put a tip jar near the register but I always ignore it.
Tip jars seem to be everywhere now. When I go to NYC, I use a garage called "Park and Lock". You drive in, get a ticket for your car, find your own spot, park, take your keys with you and leave. When you return, you get the ticket validated, pay your fee, get your car yourself, and drive off.
One day, a tip jar appeared, and I always ignore it. I drive myself in, find my own spot, park, and then get the car myself to leave. The only thing the cashier does is ring up my purchase. What exactly would I be tipping them for?