Over a coffee and a brandy he told me one day that two of them had actually gone to the town hall in Denia and informed startled officials that their papers were out of order.

That doesn't sound like german tourists to me... a german tourist runs around in shorts, with sandals (and socks!), has a camera hanging in front of his huge belly and expects everyone to speak german...
And if somethings wrong with their papers they would search someone to complain to - or about... as long as they can complain...