I agree with you and I think he was more baffled about trying to pay than the tax itself. Which it is a very real problem in Germany for foreigners. Everything is too local if you don’t have EC Karte you cannot pay. But that the baffling part, if you are a Customs office you need to accept ANY kind of payment, specifically something as standard as a Credit Card.
I disagree in this case, he tried to pay and he had to hunt down 2 different ATMs because the Customs office couldn’t accept his credit card.