What is the right course of action?

When overtaking on a German Autobahn or similar multi-lane roads, you should complete the overtaking maneuver smoothly and as swiftly as is safe, without unnecessary delays or sudden braking. It is correct to quickly continue overtaking when you have already started the maneuver, as long as there are no hazards ahead and you are not exceeding the speed limit or driving aggressively. Suddenly braking or pulling back to the right would be unsafe unless there is an immediate danger. German traffic rules also permit you to stay in the left lane while overtaking several slower vehicles in a row without having to move back in between. In summary, once you have started overtaking and the situation remains safe, you should complete it promptly and return to the right lane afterward.