Usually the train driver is in radio contact with central control and can request changes to the points, signals etc so they can make unscheduled stops. For example if there's a medical emergency on board and a passenger needs to be transferred to an ambulance.

Of course doing this can have ripple effects on other services, and if a common factor has severely delayed dozens of different trains, the central control room might not have enough staff to deal with dozens of unscheduled stop requests.

Also everyone complains about punctuality. A train stopping "nilly willy" somewhere it's not scheduled can very much cause exactly that in such a tightly scheduled system. So if you can, you avoid it.

Since we don't know "the other side of the story", we can't really tell. All people here see is the "I got kidnapped". If the story was written from the control room person's perspective, they might write a fascinating story about how they single-handedly avoided 17 trains being late by sending one train on a detour.

Would be awesome if there was someone on HN that knows if DB actually has the capacity to run a scheduling algorithm for their network within a few minutes, repeatedly, for many different trains at a moments notice. What kind of infra do they have for that, what do they use? With a large, interconnected, network that's tightly scheduled already that can't be easy.

OP was also unlucky in that he was on a regional train. They prioritize long distance trains usually as a regional train can more easily wait on a lower speed limit track somewhere than a fast long distance train on a potentially shared single track bottleneck.

Best example of this is when they hit someone. Train has to stop, control center has no say in it.

(For longer “technical” delays, keep an eye out for emergency vehicles without their sirens on.)