Why do you have to continue to brake?

Your answer is correct because you identified both reasons for continuing to brake: the refusing truck and the blue truck pulling out. According to German traffic rules, even if you have the right-of-way, you must always drive cautiously and be prepared to yield if another road user endangers safety. The truck is signaling and moving into your lane unexpectedly, which creates a hazard. Therefore, you must brake to avoid a collision. The cyclist mentioned is not the immediate cause for braking here. This rule emphasizes defensive driving and prioritizing safety over strict adherence to right-of-way.