MS offered Munich Windows completely free, or even offered to pay for the transition.
MS probably also offered the decision makers free travel around the world, free laptops and other gear, and some under the table money for being "convinced". This was done in my University so I could only imagine what will be with a big city like this.
The decision makers argument that given that Windows is "free"(first dose s free until you are hooked) and Linux takes development money (to German developers)then it is a better decision to just switch.
It is quite significant that there is so many Linux mini distros in government, instead of uniting and solving the general problems Linux have on a State or even multi State.
E.g Solving the program to handle mail,calendar and contacts is common for Spain, French, German and UK gobertment. Why can't they work together to solve it?