Having lived in Amsterdam for 15 years I can tell you that is exactly the way they go on. You are lucky they only came with one large camper as those Dutchies usually travel in multiple couples and they all love to camp, another thing they all have in common is they are all, CHEAP.
They smile to your face and stab you in the back, back stabbers. Latest is now to ring the "HOT LINE" and turn in your neighbour in for running a vacation rental, get bonus points for multiple neighbours. It's like back in WW2 when they turned in all their Jewish Neighbours.
I can feel my blood beginning to boil so I better get off the Dutch subject.
An amazing country except for the people.
I'm not Dutch hater but want them to respect my country
I'm not a Dutch hater either I just cannot stand them. There is even a book published called "Dealing with the Dutch" which says it all.