In defense of the Munich police (which is not always friendly but mostly respectful), the current situation in Bavaria is quite unusual due to the refugee crisis and the arrival of thousands of unregistered people every day, which might cause some people in the police force to be a bit on the edge.
Being checked when entering Germany from the Netherlands isn't so unusual though, as there are lots of people trafficking drugs across the border (mostly on a small scale though). Friends of mine got checked several times as well even though they're "European looking", but I haven't heard from cases where people got taken to a police station for further inquiry.
As a German I'm sorry that this happened, because I actually think we got one of the most friendly and helpful police forces in Europe.
Concerning your dismissal at the police station: As far as I know you would have had the right to be driven back to your original location in Munich afterwards. My advice: Complain. In Germany, this is the best way to get what you want :D
Being checked when entering Germany from the Netherlands isn't so unusual though, as there are lots of people trafficking drugs across the border (mostly on a small scale though). Friends of mine got checked several times as well even though they're "European looking", but I haven't heard from cases where people got taken to a police station for further inquiry.
As a German I'm sorry that this happened, because I actually think we got one of the most friendly and helpful police forces in Europe.
Concerning your dismissal at the police station: As far as I know you would have had the right to be driven back to your original location in Munich afterwards. My advice: Complain. In Germany, this is the best way to get what you want :D