About The real hierarchy: who overrules whom on priority?: which statement is WRONG?
The order is: traffic controller, then traffic lights, then signs, then the rules; a controller who is present overrides the signs.
You must always obey a red traffic light, even if a traffic controller or police officer waves you through with a hand signal.
Traffic signs are used precisely WHEN the traffic rules (such as the rechts-regel) are not sufficient.
Explanation
trap: light over officer. Instructions from an authorised officer or traffic controller override traffic lights, which in turn override signs. At a hand signal from the officer, you follow the officer, not the red light