I am confused about the following in Captain America: Civil War:
After the attack in Vienna, they find Bucky in Bucharest. But why was the German police there? Why wasn't it the Romanian police arresting them?
I am very sure this was a mistake made during production. Regular German police will not operate outside Germany. On the other hand the Volkswagen Beetle Cap is driving in Berlin does not have a german license plate.
The “German Special Forces” are probably GSG-9. They are a division of the border police (that's the literal) name, which were founded after the PLO's terrorist attack at the 1972 Munich olympics.
They are special forces in the sense that their training includes urban fighting and military training, but they are police because the military is forbidden to operate within Germany.
They do operate outside the country - their first big mission was in Mogadishu, after all - but with the consent of the local government.
I guess it's simplest to assume that the were there with the permission of the Romanian government.
Why would the Romanian government consent to allow German Special Forces to arrest Bucky, when the country had its own special forces units? Or better yet, why not have U.N. forces arrest Bucky? The bombing had occurred in Vienna, Austria; not Germany; and the U.N. played a major role in the creation of the Sokovia Accords.
I think this was a case of a blooper. Every movie has its bloopers. And this was one of the bloopers featured in "CIVIL WAR".